Color agent for road marking material and road marking material using the same

ABSTRACT

A color agent for a road marking material comprising composite particles having an average particle diameter of 0.01 to 10.0 μm, said composite particles comprising: inorganic particles; a gluing agent coating layer formed on surface of said inorganic particle; and an organic pigment coat formed onto said gluing agent coating layer in an amount of from 1 to 500 parts by weight based on 100 parts by weight of said inorganic particles. The color agent for a road marking material, contains no harmful elements and exhibits excellent tinting strength, hiding power, light resistance and heat resistance, and is suppressed in surface activity thereof. The road marking material using the color agent, shows a less change in hue with the passage of time and an excellent retroreflective property.

BACKGROUND OF THE INVENTION

The present invention relates to a color agent for a road markingmaterial and a road marking material using the color agent. Moreparticularly, to a color agent for a road marking material, whichcontains no harmful elements and exhibits excellent tinting strength,hiding power, light resistance and heat resistance, and which issuppressed in surface activity thereof, and a road marking materialusing the color agent, which shows a less change in hue with the passageof time and an excellent retroreflective property.

Hitherto, white or yellow road marking materials have been used to formzone lines, road signs, etc., for the purpose of obeying traffic lawsand regulations and preventing or minimizing traffic accidents.

On the other hand, in recent years, various characters or complicatedmarks have been frequently used in Japan as road markings. Thus, green-or brick-colored road marking materials have been applied to schoolzones, bicycle roads, etc. Further, in Japan it has been demanded to usedesigned color marks in community squares, shopping roads, joggingcourses, cycling roads, promenades, parks, etc., in order to expectenvironmental beautification or PR effects.

The road marking materials are classified into cold-applied paint-types(first class), heat-applied paint-types (second class) and melt types(third class) according to JIS K 5665. Further, corresponding to theabove color marks, there are known adhesion-type road marking materialssuch as heat-adhesion types and cold-adhesion types.

Any of the above road marking materials is used outdoors for a longperiod of time and, therefore, is required to have a less change in huewith the passage of time after application to roads. It is known thatthe change in hue of the road marking materials is caused bydiscoloration of color agents or deterioration of resins due toultraviolet radiation or acid rain, deterioration of resins due to highsurface activity of color agents, or the like. Thus, the color agentsused in the road marking materials are required to exhibit a highweather resistance as well as a low surface activity.

Also, among the above-mentioned road marking materials, the melt-typeroad marking materials (third class) are heated and molten at atemperature as high as about 200° C. For this reason, color agents usedin such melt-type road marking materials are required to show a heatresistance capable of preventing discoloration thereof even when heatedat such a high temperature.

In addition, in order to shield a road surface made of asphalt orconcrete and allow a road surface to show the aimed hue, the coloragents used in the above road marking materials are also required tohave excellent hiding power and tinting strength.

Among the road marking materials, the yellow road marking materials fortraffic signs are especially important to users, since the yellow coloris intended to indicate regulations or cautions on traffic. The hue ofthe yellow color used for these purposes is unified as a common “yellowfor traffic signs or markings” by the National Police Agency in Japan.

The yellow road marking materials tend to be deteriorated inreflectivity as compared to white road marking materials. In particular,it is known that when only a small amount of light emitted fromheadlight or street lamps such as mercury lamp and sodium lamp ispresent during the night, the visibility of the yellow markings isconsiderably low as compared to that during the daytime. Therefore, thecolor agents used in the yellow road marking materials are required tobe free from discoloration even when exposed to a long-term outdoor useand when melted under a high temperature condition, to show a hue lyingwithin the common “yellow for traffic signs or markings”, and to have anexcellent night reflectivity.

At present, lead chromate has been mainly used as pigments for theyellow road marking materials because of not only excellent heatresistance and weather resistance but also clear hue thereof. However,the lead chromate contains heavy metals such as chromium and lead. Forthis reason, it has been demanded to provide alternate yellow pigmentsfrom the standpoints of hygiene, safety and prevention of environmentalpollution.

As yellow pigments for road marking materials other than lead chromate,there are known inorganic pigments such as titanium yellow, iron oxidehydroxide and bismuth vanadate; and yellow-based organic pigments suchas azo-based, isoindolinone-based and anthraquinone-based pigments.

However, although the above inorganic pigments are excellent in heatresistance and weather resistance, these pigments tend to bedeteriorated in tinting strength, thereby failing to show a clear hue.On the other hand, the above organic pigments usually show a clear hue,but tend to be deteriorated in hiding power as well as heat resistanceand light resistance. Thus, any of the conventional inorganic andorganic pigments fails to satisfy properties required as alternatematerials of lead chromate. Further, it is known that road markingmaterials using such color agents tend to be deteriorated in visibilityduring the night.

Hitherto, in order to obtain pigments as alternate materials of leadchromate which are free from environmental pollution, and improved inweather resistance and heat resistance as well as visibility during thenight, it has been attempted to combine the inorganic pigments with theorganic pigments (Japanese Patent Application Laid-Open (KOKAI) Nos.4-132770(1992), 7-331113(1995), 8-209030(1996), 9-100420(1997) and2001-220550, etc.).

At present, it has been strongly required to provide a color agent for aroad marking material which shows a less change in hue with the passageof time and is capable of producing such a road marking materialexhibiting an excellent retroreflective property. However, such coloragent has not been obtained until now.

That is, in the methods described in Japanese Patent ApplicationLaid-Open (KOKAI) Nos. 4-132770(1992) and 9-100420(1997), since organicpigments are precipitated in the presence of an inorganic pigment toform a organic pigment layer on the surface of the inorganic pigment,the organic pigments fail to have a sufficient adhesion strength to theinorganic pigments as shown in the below-mentioned Comparative Examples.Further, since the obtained color agent has a high surface activity, theroad marking material produced from such a color agent tends to undergoa large change in hue with the passage of time.

Also, in the method described in Japanese Patent Application Laid-Open(KOKAI) No. 7-331113(1995), organic pigments are charged together withinorganic pigments having a refractive index of not less than 2.2 and acoupling agent into a mixer, and stirred and mixed together therein toadhere the organic pigments onto the surface of the inorganic pigments.However, as shown in the below-mentioned Comparative Examples, theadhesion strength of the organic pigments onto the inorganic pigmentstends to become insufficient as compared to the color agent for a roadmarking material according to the present invention in which organicpigments are adhered onto the surface of inorganic particles through agluing agent coating layer. Therefore, a road marking material producedfrom the above conventional color agent may fail to show sufficientalkali resistance, abrasion resistance and aging resistance.

In addition, in Japanese Patent Application Laid-Open (KOKAI) Nos.8-209030(1996) and 2001-220550, there are described heat-melting typeroad marking paints comprising caking resin, color agent and filler inwhich a pigment composition containing organic and inorganic pigments isused as the color agent. However, in these prior publications, thesurface activity of the color agent is not taken into consideration.Therefore, it is suggested that the road marking material produced fromsuch a color agent tends to undergo a large change in hue with thepassage of time.

Meanwhile, in Japanese Patent Application Laid-Open (KOKAI) No.2001-262297, there are described composite particles produced byadhering organic pigments onto the surface of white inorganic particlesthrough a gluing agent. However, the object of this KOKAI is to suppressdesorption of the organic pigments from the surface of the whiteinorganic particles, and this KOKAI is silent in the surface activity ofthe obtained composite particles.

As a result of the present inventors' earnest studies, it has been foundthat when composite particles having an average particle diameter of0.01 to 10.0 μm which are produced by adhering 1 to 500 parts by weightof organic pigments onto 100 parts by weight of inorganic particlesthrough a gluing agent and which may be further coated with a fattyacid, a fatty acid metal salt or a coupling agent, are used as a coloragent for a road marking material, the obtained road marking materialcan show a less change in hue with the passage of time and an excellentretroreflective property. The present invention has been attained on thebasis of the finding.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a color agent for aroad marking material which contains no harmful elements, exhibitsexcellent tinting strength, hiding power, light resistance and heatresistance, and is suppressed in its surface activity.

Another object of the present invention is to provide a road markingmaterial having a less change in hue with the passage of time andexhibiting an excellent retroreflective property.

To accomplish the aims, in a first aspect of the present invention,there is provided a color agent for a road marking material comprisingcomposite particles having an average particle diameter of 0.01 to 10.0μm, said composite particles comprising:

inorganic particles;

a gluing agent coating layer formed on surface of said inorganicparticle; and

an organic pigment coat formed onto said gluing agent coating layer inan amount of from 1 to 500 parts by weight based on 100 parts by weightof said inorganic particles.

In a second aspect of the present invention, there is provided a coloragent for a road marking material comprising composite particles havingan average particle diameter of 0.01 to 10.0 μm, said compositeparticles comprising:

inorganic particles;

a gluing agent coating layer formed on surface of said inorganicparticle;

an organic pigment coat formed onto said gluing agent coating layer inan amount of from 1 to 500 parts by weight based on 100 parts by weightof said inorganic particles; and

a surface coating layer composed of at least one material selected fromthe group consisting of a fatty acid, a fatty acid metal salt and acoupling agent, which is formed on said organic pigment coat in anamount of 0.1 to 10.0% by weight based on the total weight of thecomposite particles including the surface coating layer.

In a third aspect of the present invention, there is provided a roadmarking material comprising a binder resin, the color agent as definedin the first aspect and a filler, said color agent being contained in anamount of 0.1 to 60% by weight based on the weight of the road markingmaterial.

In a fourth aspect of the present invention, there is provided a roadmarking material comprising a binder resin, the color agent as definedin the second aspect and a filler, said color agent being contained inan amount of 0.1 to 60% by weight based on the weight of the roadmarking material.

In a fifth aspect of the present invention, there is provided in amethod of forming a road marking material comprising a binder resin, acolor agent and a filler, the improvement comprising using as said coloragent, composite particles having an average particle diameter of 0.01to 10.0 μm, said composite particles comprising:

inorganic particles;

a gluing agent coating layer formed on surface of said inorganicparticle; and

an organic pigment coat formed onto said gluing agent coating layer inan amount of from 1 to 500 parts by weight based on 100 parts by weightof said inorganic particles.

In a sixth aspect of the present invention, there is provided in amethod of forming a road marking material comprising a binder resin, acolor agent and a filler, the improvement comprising using as said coloragent, composite particles having an average particle diameter of 0.01to 10.0 μm, said composite particles comprising:

inorganic particles;

a gluing agent coating layer formed on surface of said inorganicparticle;

an organic pigment coat formed onto said gluing agent coating layer inan amount of from 1 to 500 parts by weight based on 100 parts by weightof said inorganic particles; and

a surface coating layer composed of at least one material selected fromthe group consisting of a fatty acid, a fatty acid metal salt and acoupling agent, which is formed on said organic pigment coat in anamount of 0.1 to 10.0% by weight based on the total weight of thecomposite particles including the surface coating layer.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be described in detail below.

First, the color agent for a road marking material according to thepresent invention is described.

The color agent for a road marking material according to the presentinvention is composed of composite particles comprising inorganicparticles as core particles, a gluing agent coating layer formed on thesurface of the inorganic particles, and an organic pigment coat adheredonto the gluing agent coating layer.

Meanwhile, in the color agent for a road marking material according tothe present invention, a plurality of coloring adhesion layers composedof the organic pigments as the organic pigment coat may be formed on thesurface of the inorganic particle as core particles in order to attainthe aimed hue. For example, after forming the gluing agent coating layeron the surface of the inorganic particle, an organic pigment coat(hereinafter referred to merely as “first coloring adhesion layer”) isformed by adhering the organic pigments onto the gluing agent coatinglayer (the inorganic particles on which the first coloring adhesionlayer is formed is hereinafter referred to as “intermediate particles”).Then, after further forming a gluing agent coating layer on the firstcoloring adhesion layer, an organic pigment coat (hereinafter referredto merely “second coloring adhesion layer”) is formed by adhering theorganic pigments onto the gluing agent coating layer. The same procedureas described above may be repeated to form at least one additionalcoloring adhesion layer on the surface of the inorganic particles, ifrequired. Hereinafter, the composite particles having two or morecoloring adhesion layers are referred to as “composite particles havinga plurality of coloring adhesion layers”.

As the inorganic particles used in the present invention, there may beexemplified white pigments such as titanium dioxide, zirconium oxide andzinc oxide; extender pigments such as fine silica particles such assilica powder, white carbon, fine silicic acid powder and diatomaceousearth, clay, calcium carbonate, barium sulfate, alumina white, talc andtransparent titanium oxide; and inorganic pigments such as titaniumyellow, hematite and iron oxide hydroxide. These inorganic particles maybe used singly or in the form of a mixture of any two or more thereof.Among these inorganic particles, in the consideration of the contrastratio and retroreflective property of the obtained road markingmaterial, the preferred inorganic particles are titanium dioxideparticles. Also, mixed inorganic particles containing titanium dioxideparticles and inorganic particles containing titanium dioxide arepreferred.

The inorganic particles may have any suitable shape, and, for example,may be spherical particles, granular particles, polyhedral particles,acicular particles, spindle-shaped particles, rice ball-like particles,flake-shaped particles, scale-like particles or plate-shaped particles.

The average particle diameter of the inorganic particles is usually 0.01to 10.0 μm, preferably 0.02 to 9.5 μm, more preferably 0.03 to 9.0 μm.When the average particle diameter of the inorganic particles is morethan 10.0 μm, the obtained color agent for a road marking materialbecomes coarse particles, resulting in deteriorated tinting strengththereof. When the average particle diameter of the inorganic particlesis less than 0.01 μm, the inorganic particles tend to be agglomerateddue to such fine particles. As a result, it may become difficult to forma uniform gluing agent coating layer on the surface of the inorganicparticles, and uniformly adhere the organic pigments onto the surface ofthe gluing agent coating layer.

The inorganic particles preferably have a BET specific surface areavalue of preferably not less than 0.5 m²/g. When the BET specificsurface area value is less than 0.5 m²/g, the inorganic particles tendto become coarse particles, or sintering tends to be caused within orbetween the particles, so that the obtained color agent for a roadmarking material also tends to become coarse particles and, therefore,be deteriorated in tinting strength. In the consideration of tintingstrength of the obtained color agent for a road marking material, theBET specific surface area value of the inorganic particles is morepreferably not less than 1.0 m²/g, still more preferably 1.5 m²/g. Inthe consideration of forming a uniform gluing agent coating layer on thesurface of the inorganic particles or uniformly adhering the organicpigments onto the surface of the gluing agent coating layer, the upperlimit of the BET specific surface area value of the inorganic particlesis preferably 500 m²/g, more preferably 400 m²/g, still more preferably300 m²/g.

The refractive index of the inorganic particles used in the presentinvention may be appropriately selected according to aimed applicationsof the color agent for a road marking material. In the consideration ofcolor-developing property and retroreflective property of the obtainedcolor agent for a road marking material, there may be preferably usedmixed inorganic particles produced by mixing white pigments having arefractive index of not less than 2.0 with extender pigments having arefractive index of less than 2.0. In particular, in order to obtain aroad marking material requiring a high retroreflective property, it ispreferred to use inorganic particles having a higher retroreflectiveproperty. In such a case, the refractive index of the inorganicparticles is preferably not less than 2.0, more preferably not less than2.2.

The hue of the inorganic particles used in the present invention may beappropriately selected according to the aimed hue of the color agent fora road marking material. For example, the L* value thereof is preferablynot less than 30.0, and the C* value thereof is preferably not more than70.0. In the consideration of the visibility during the night of theobtained road marking material, the L* value of the inorganic particlesis more preferably not less than 50.0, still more preferably not lessthan 60.0, further still more preferably not less than 70.0. In theconsideration of color toning, the C* value of the inorganic particlesis more preferably not more than 20.0, still more preferably not morethan 15.0, further still more preferably not more than 10.0.

The hiding power of the inorganic particles used in the presentinvention may be appropriately selected according to the aimedapplications of the color agent for a road marking material. Forexample, in the case where the color agent is used in such applicationsrequiring a delicate hue or a hue much closer to an original color oforganic pigments adhered onto the inorganic particles, the hiding powerthereof is preferably less than 400 cm²/g, more preferably not more than300 cm²/g, still more preferably not more than 200 cm²/g. In the casewhere the color agent is used in such applications requiring a highhiding power, the hiding power of the inorganic particles is preferablynot less than 400 cm²/g, more preferably not less than 600 cm²/g, stillmore preferably not less than 800 cm²/g.

As to the light resistance of the inorganic particles used in thepresent invention, the lower limit of the ΔE* value thereof is usuallymore than 5.0, and the upper limit of the ΔE* value is usually 12.0,preferably 11.0, more preferably 10.0 when measured by thebelow-mentioned evaluation method.

The gluing agent used in the present invention may be of any kind aslong as the organic pigment can be adhered onto the surface of theinorganic particles therethrough. Examples of the preferred gluingagents may include organosilicon compounds such as alkoxysilanes,fluoroalkylsilanes and polysiloxanes; various coupling agents such assilane-based coupling agents, titanate-based coupling agents,aluminate-based coupling agents and zirconate-based coupling agents;oligomer compounds; polymer compounds; or the like. These gluing agentsmay be used singly or in the form of a mixture of any two or morethereof. In the consideration of adhesion strength of the organicpigments onto the surface of the inorganic particle through the gluingagent coating layer, the more preferred gluing agents are theorganosilicon compounds such as alkoxysilanes, fluoroalkylsilanes andpolysiloxanes, and various coupling agents such as silane-based couplingagents, titanate-based coupling agents, aluminate-based coupling agentsand zirconate-based coupling agents, and still more preferred gluingagents are the organosilicon compounds such as alkoxysilanes,fluoroalkylsilanes and polysiloxanes.

As the organosilicon compounds used in the present invention, there maybe exemplified organosilane compounds obtained from alkoxysilanecompounds represented by the below-mentioned formula (I), polysiloxanesrepresented by the below-mentioned formula (II), modified polysiloxanesrepresented by the below-mentioned formula (III), terminal-modifiedpolysiloxanes represented by the below-mentioned formula (IV),fluoroalkylsilanes represented by the below-mentioned formula (V), ormixtures thereof.R¹ _(a)SiX_(4−a)  (I)wherein

R¹: C₆H₅—, (CH₃)₂CHCH₂— or n-C_(m)H_(2m+1)—;

X: CH₃O— or C₂H₅O—;

m: an integer of 1 to 18; and

a: an integer of 0 to 3

Specific examples of the alkoxysilanes may includemethyltriethoxysilane, dimethyldiethoxysilane, phenyltriethyoxysilane,diphenyldiethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane,phenyltrimethoxysilane, diphenyldimethoxysilane,isobutyltrimethoxysilane, decyltrimethoxysilane or the like.

In the consideration of the adhesion strength of the organic pigmentsonto the surface of the inorganic particles, the organosilane compoundsobtainable from methyltriethoxysilane, methyltrimethoxysilane,dimethyldimethoxysilane, isobutyltrimethoxysilane andphenyltriethyoxysilane are more preferred, and the organosilanecompounds obtainable from methyltriethoxysilane, methyltrimethoxysilaneand phenyltriethyoxysilane are most preferred.

wherein

R¹: H, CH₃; and

v: 15 to 450

wherein

R³, R⁶ and R⁷: —(—CH₂—)_(l)— and may be the same or different;

R⁴ and R⁸: —(—CH₂—)_(m)—CH₃;

R⁵: —OH, —COOH, —CH═CH₂, —C═CH₃ or —(—CH₂—)_(n)—CH₃;

l: 1 to 15;

m, n: 0 to 15;

w: 1 to 50; and

x: 1 to 300

wherein

R⁹ and R¹⁰: —OH, R¹²OH or R¹³COOH and may be the same or different;

R¹¹: —CH₃ or —C₆H₅;

R¹² and R¹³: —(—CH₂—)_(p)—;

l: 1 to 15;

y: 1 to 200; and

z: 0 to 100

In the consideration of the adhesion strength of the organic pigmentsonto the surface of the inorganic particles, polysiloxanes having methylhydrogen siloxane units, polyether-modified polysiloxanes and carboxylicacid-terminal-modified polysiloxanes are preferred.

Specific examples of the fluoroalkylsilanes may include trifluoropropyltrimethoxysilane, tridecafluorooctyl trimethoxysilane,heptadecafluorodecyl trimethoxysilane, heptadecafluorodecylmethyldimethoxysilane, trifluoropropylethoxysilane, tridecafluorooctyltriethoxysilane, heptadecafluorodecyl triethoxysilane or the like.

In the consideration of the adhesion strength of the organic pigmentsonto the surface of the inorganic particles, the fluorine-containingorganosilane compounds obtainable from trifluoropropyl trimethoxysilane,tridecafluorooctyl trimethoxysilane and heptadecafluorodecyltrimethoxysilane are more preferred, and the fluorine-containingorganosilane compounds obtainable from trifluoropropyl trimethoxysilaneand tridecafluorooctyl trimethoxysilane are most preferred.

wherein

R¹⁴: —CH₃, —C₂H₅;

m: 0 to 15; and

n: 1 to 3

Among the coupling agents, as the silane-based coupling agents, theremay be exemplified vinyltrimethoxysilane, vinyltriethoxysilane,γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane,γ-mercaptopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane,N-β(aminoethyl)-γ-aminopropyltrimethoxysilane,γ-glycidoxypropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane,or the like.

As the titanate-based coupling agents, there may be exemplifiedisopropyltristearoyl titanate,isopropyltris(dioctylpyrophosphate)titanate,isopropyltri(N-aminoethyl-aminoethyl)titanate,tetraoctylbis(ditridecylphosphate)titanate,tetra(2,2-diaryloxymethyl-1-butyl)bis(ditridecyl)phosphate titanate,bis(dioctylpyrophosphate)oxyacetate titanate,bis(dioctylpyrophosphate)ethylene titanate, or the like.

As the aluminate-based coupling agents, there may be exemplifiedacetoalkoxyaluminum diisopropylate,aluminumdiisopropoxymonoethylacetoacetate,aluminumtrisethylacetoacetate, aluminumtrisacetylacetonate, or the like.

As the zirconate-based coupling agents, there may be exemplifiedzirconiumtetrakisacetylacetonate, zirconiumdibutoxybisacetylacetonate,zirconiumtetrakisethylacetoacetate,zirconiumtributoxymonoethylacetoacetate,zirconiumtributoxyacetylacetonate, or the like.

It is preferred to use oligomer compounds having a molecular weight offrom 300 to less than 10,000. It is preferred to use polymer compoundshaving a molecular weight of about 10,000 to about 100,000. In theconsideration of forming a uniform coating layer on the inorganicparticles, the oligomer compounds or polymer compounds are preferably ina liquid state, or soluble in water or various solvents.

The amount of the gluing agent coating layer is preferably 0.01 to 15.0%by weight, more preferably 0.02 to 12.5% by weight, still morepreferably 0.03 to 10.0% by weight (calculated as C) based on the weightof the gluing agent-coated inorganic particles. When the amount of thegluing agent coating layer is less than 0.01% by weight, it may bedifficult not only to adhere not less than one part by weight of theorganic pigments onto 100 parts by weight of the inorganic particles,but also to reduce the surface activity to the desired value. Since thegluing agent coating layer coated on the inorganic particles in anamount up to 15% by weight enables 1 to 500 parts by weight of theorganic pigments to adhere onto 100 parts by weight of the inorganicparticles therethrough, it is not necessary to form the gluing agentcoating layer in an amount of more than 15.0% by weight.

As the organic pigments used in the present invention, there may beexemplified various organic pigments ordinarily used as color agents ofpaints and resin compositions, such as organic red-based pigments,organic blue-based pigments, organic yellow-based pigments, organicgreen-based pigments, organic orange-based pigments, organic brown-basedpigments and organic violet-based pigments.

In particular, in the case of the color agent for yellow-based roadmarking material which is used as an alternate material of leadchromate, in order to adjust the hue thereof to the common “yellow fortraffic signs or markings”, there may be used at least one kind oforganic pigments selected from the group consisting of organicyellow-based pigments, organic orange-based pigments and organicred-based pigments.

Among various organic pigments mentioned above, examples of the organicred-based pigments may include azo-based pigments such as permanentcarmine and permanent red, condensed azo pigments such as condensed azored, condensed polycyclic pigments such as quinacridon-based pigments,perylene-based pigments, perinone-based pigments, anthraquinone-basedpigments, isoindolinone-based pigments, diketo-pyrrolo-pyrrole-basedpigments, or the like.

Examples of the organic blue-based pigments may includephthalocyanine-based pigments such as metal-free phthalocyanine blue,phthalocyanine blue and fast sky blue, alkali blue or the like.

Examples of the organic yellow-based pigments may include monoazo-basedpigments such as Hanza yellow, disazo-based pigments such as benzidineyellow and permanent yellow, condensed azo pigments such as condensedazo yellow, condensed polyciclyic-based pigments such asisoindolinone-based pigments, isoindoline-based pigments,quinophthalone-based pigments, anthraquinone-based pigments, or thelike.

Examples of the organic green-based pigments may includephthalocyanine-based pigments such as phthalocyanine green, or the like.

Examples of the organic orange-based pigments may include azo-basedpigments such as permanent orange, lithol fast orange and vulcan fastorange, or the like.

Examples of the organic brown-based pigments may include azo-basedpigments such as permanent brown and para-brown, or the like.

Examples of the organic violet-based pigments may include azo-basedpigments such as fast violet, or the like.

Meanwhile, these organic pigments may be used in the form of a mixtureof any two or more thereof depending upon the hue required. Also, amixture composed of two or more organic pigments showing the similarkind of color may be used depending upon the hue and propertiesrequired.

Meanwhile, in the color agent for a road marking material which has aplurality of coloring adhesion layers, the organic pigments used in thefirst coloring adhesion layer may be the same as those used in thesecond or subsequent coloring adhesion layer, may be identical in colorbut different in kind from those used in the second or subsequentcoloring adhesion layer, or different in color from those used in thesecond or subsequent coloring adhesion layer.

The total amount of the organic pigments adhered is usually 1 to 500parts by weight, preferably 5 to 400 parts by weight, more preferably 10to 300 parts by weight based on 100 parts by weight of the inorganicparticles. When the total amount of the organic pigments adhered is lessthan one part by weight, the amount of the organic pigments adhered ontothe surface of the inorganic particles is too small, so that it maybecome difficult to obtain the aimed color agent for a road markingmaterial of the present invention which has a high tinting strength.When the total amount of the organic pigments adhered is more than 500parts by weight, the organic pigments adhered tend to be desorbed fromthe inorganic particles because of too large amount of the organicpigments adhered. As a result, the obtained color agent for a roadmarking material may be deteriorated in dispersibility in the roadmarking material, so that it may be difficult to obtain a road markingmaterial having a uniform hue.

In the case of the color agent for a road marking material having aplurality of coloring adhesion layer, the amount of the organic pigmentsadhered in each coloring adhesion layer may be appropriately selecteddepending upon the hue and properties required, and within such a rangethat the total amount of the organic pigments adhered falls in theabove-specified range.

The shape and size of the color agent for a road marking materialaccording to the present invention may vary depending upon those of theinorganic particles as core particles. The color agent for a roadmarking material usually have a configuration or shape similar to thatof the core particles.

Specifically, the average particle diameter of the color agent for aroad marking material according to the present invention is usually 0.01to 10.0 μm, preferably 0.02 to 9.5 μum, more preferably 0.03 to 9.0 μm.When the average particle diameter of the color agent for a road markingmaterial is more than 10.0 μm, the color agent for a road markingmaterial tends to be deteriorated in tinting strength because of toolarge particle size thereof. When the average particle diameter of thecolor agent for a road marking material is less than 0.01 μm, the coloragent for a road marking material tends to be agglomerated together dueto such fine particles, so that it may become difficult to well dispersethe color agent in the road marking material.

The BET specific surface area value of the color agent for a roadmarking material according to the present invention is preferably 0.5 to500 m²/g, more preferably 1.0 to 400 m²/g, still more preferably 1.5 to300 m²/g. When the BET specific surface area value of the color agentfor a road marking material is less than 0.5 m²/g, the color agent tendsto become coarse particles, or sintering tends to be caused within orbetween the particles, so that the obtained color agent tends to bedeteriorated in tinting strength.

The lightness of the color agent for a road marking material accordingto the present invention considerably varies depending upon the aimedhue of the color agent for a road marking material and, therefore, isnot exactly determined. Nevertheless, the higher lightness of the coloragent can lead to a more excellent visibility during the night. Inparticular, in the case of the yellow-based road marking material, theL* value thereof is preferably not less than 40.0, more preferably notless than 50.0, still more preferably not less than 60.0.

The tinting strength of the color agent for a road marking materialaccording to the present invention is preferably not less than 110%,more preferably not less than 115%, still more preferably not less than120% when measured by the below-mentioned evaluation method.

The hiding power of the color agent for a road marking materialaccording to the present invention is preferably not less than 200cm²/g. In the consideration of a good contrast ratio of the obtainedroad marking material, the hiding power of the color agent is morepreferably not less than 400 cm²/g, still more preferably not less than600 cm²/g, most preferably not less than 800 cm²/g.

The surface activity of the color agent for a road marking materialaccording to the present invention is preferably not more than 2%, morepreferably not more than 1.5% when measured by the below-mentionedevaluation method. When the surface activity of the color agent is morethan 2%, the resins contained in the obtained road marking material tendto be deteriorated because of a too high surface activity of the coloragent, resulting in undesirable change in hue of the road markingmaterial as well as poor strength thereof.

The heat resistance of the color agent for a road marking materialaccording to the present invention is preferably not less than 180° C.when measured by the below-mentioned evaluation method. In particular,when the color agent is applied to a melt-type road marking paintdefined in JIS K 5665 (third class), the heat resistance of the coloragent for a road marking material is preferably not less than 190° C.,more preferably not less than 200° C., still more preferably 210° C. Inthis case, when the heat-resisting temperature is less than 190° C., thepaint tends to be sometimes deteriorated during heat-melting thereof.

As to the light resistance of the color agent for a road markingmaterial according to the present invention, the ΔE* value thereof isusually not more than 5.0, preferably not more than 4.0 when measured bythe below-mentioned evaluation method. In particular, when the lightresistance (ΔE* value) of the color agent is more than 5.0, the coloragent tends to undergo discoloration upon exposure to ultraviolet light,etc. As a result, the road marking material obtained from such a coloragent tends to suffer from a large change in hue with the passage oftime after application to the road.

The desorption percentage of the organic pigments from the color agentfor a road marking material according to the present invention ispreferably not more than 20%, more preferably not more than 15%. Whenthe desorption percentage of the organic pigments from the color agentis more than 20%, the color agent tends to be prevented from beinguniformly dispersed in the paint by the desorbed organic pigments, andfurther since the hue of the inorganic particles is exposed to the outersurface of the color agent particles at portions from which the organicpigments are desorbed, it may be difficult to attain a uniform anddesirable hue thereof.

In the color agent for a road marking material according to the presentinvention, if required, the surface of the inorganic particle may bepreviously coated with at least one intermediate coating materialselected from the group consisting of hydroxides of aluminum, oxides ofaluminum, hydroxides of silicon and oxides of silicon. The color agentproduced using the inorganic particles coated with the intermediatecoating material, can be more effectively prevented from undergoingdesorption of the organic pigments from the surface of the inorganicparticle, and can be improved in heat resistance and light resistance,as compared to the color agent produced using the inorganic particlesuncoated with the intermediate coating material. Further, the roadmarking material obtained from such a color agent using the inorganicparticles coated with the intermediate coating material, can exhibit amore excellent abrasion resistance.

The amount of the intermediate coating material coated on the surface ofthe inorganic particles is preferably 0.01 to 20.0% by weight(calculated as Al, SiO₂ or a sum of Al and SiO₂) based on the weight ofthe inorganic particles coated with the intermediate coating material.When the amount of the intermediate coating material coated is less than0.01% by weight, it may be difficult to attain the aimed effects ofreducing the desorption percentage of organic pigments and improving thelight resistance. When the intermediate coating material is coated in anamount of 0.01 to 20% by weight, the effects of reducing the desorptionpercentage of organic pigments and improving the heat resistance andlight resistance can be sufficiently attained. Therefore, it is notnecessary to coat the intermediate coating material in an amount of morethan 20% by weight.

The color agent for a road marking material produced using the inorganicparticles coated with the intermediate coating material according to thepresent invention, is substantially the same in particle size, BETspecific surface area value, lightness, tinting strength, hiding powerand surface activity as those of the color agent for a road markingmaterial produced using the inorganic particles uncoated with theintermediate coating material according to the present invention. Thedesorption percentage of the organic pigments from the color agent for aroad marking material using the inorganic particles coated with theintermediate coating material, is preferably not more than 15%, morepreferably not more than 10%. As to the light resistance of the coloragent, the ΔE* value thereof is preferably not more than 4.0, morepreferably 3.0. Also, by coating such the intermediate coating materialon the surface of the inorganic particles, the heat resistance of theobtained color agent for a road marking material can be increased byabout 5 to 10° C. than that of the color agent for a road markingmaterial using the inorganic particles uncoated with the intermediatecoating material according to the present invention.

If required, the surface of the color agent for a road marking materialaccording to the present invention may be further coated with a fattyacid, a fatty acid metal salt or a silane-based coupling agent. The roadmarking material using the color agent coated with a fatty acid, a fattyacid metal salt or a silane-based coupling agent can be reduced insurface activity and can be improved in abrasion resistance as comparedwith the road marking material using the color agent uncoated therewith.

As the fatty acid used in the present invention, there may beexemplified saturated or unsaturated fatty acids, preferably saturatedor unsaturated fatty acids having 12 to 22 carbon atoms.

As the fatty acid metal salt used in the present invention, there may beexemplified salts of saturated or unsaturated fatty acids and metals.Specific examples of the fatty acid metal salt may include salts ofsaturated or unsaturated fatty acids having 12 to 22 carbon atoms withalkali earth metals such as magnesium, calcium, strontium and barium,alkali metals such as lithium, sodium and potassium, or metals such asaluminum, copper, iron, lead and tin. In the consideration of goodabrasion resistance of the obtained road marking material, the preferredfatty acid metal salts are salts of stearic acid with alkali earthmetals, or zinc stearate.

As the silane-based coupling agent used in the present invention, theremay be exemplified those compounds ordinarily blended in resincompositions. Examples of the silane-based coupling agent may includeγ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane,vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane,γ-chloropropyltrimethoxysilane, γ-chloropropylmethyldichlorosilane,γ-chloropropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane,γ-glycidoxypropyltrimethoxysilane,γ-glycidoxypropylmethyldiethoxysilane,γ-methacryloxypropyltrimethoxysilane,γ-methacryloxypropylmethyldimethoxysilane,N-β(aminoethyl)-γ-aminopropyltrimethoxysilane,N-β(aminoethyl)-γ-aminopropylmethyldimethoxysilane,vinyltris(β-methoxyethoxy)silane,β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,N-phenyl-γ-aminopropyltrimethoxysilane or the like.

The amount of the fatty acid, fatty acid metal salt or silane-basedcoupling agent coated on the color agent is preferably 0.1 to 10.0% byweight, more preferably 0.2 to 7.5% by weight, still more preferably 0.3to 5.0% by weight (calculated as C) based on the weight of the coloragent coated with the fatty acid, fatty acid metal salt or silane-basedcoupling agent. When the amount of the fatty acid, fatty acid metal saltor silane-based coupling agent coated on the color agent is less than0.1% by weight, it may be difficult to further reduce the surfaceactivity thereof, and attain the effect of improving an abrasionresistance of the obtained road marking material. Even though the fattyacid, fatty acid metal salt or silane-based coupling agent is coated onthe color agent in an amount of more than 10.0% by weight, since theeffects of reducing the surface activity and improving the abrasionresistance of the road marking material is already saturated, it is notnecessary to coat such a large amount of the fatty acid, fatty acidmetal salt or silane-based coupling agent on the color agent.

The color agent for a road marking material whose surface is furthercoated with the fatty acid, fatty acid metal salt or silane-basedcoupling agent according to the present invention, is substantially thesame in particle size, BET specific surface area value, lightness,tinting strength, hiding power, heat resistance, light resistance anddesorption percentage of organic pigments as those of the color agentfor a road marking material according to the first aspect of the presentinvention whose surface is not coated therewith. For example, the coloragent for a road marking material whose surface is further coated withthe fatty acid, fatty acid metal salt or silane-based coupling agent,has an average particle diameter of usually 0.01 to 10.0 μm, preferably0.02 to 9.5 μm and a BET specific surface area value of preferably 0.5to 500 m²/g, preferably 1.0 to 400 m²/g. In particular, in the case ofthe color agent for yellow-based road marking material, the L* valuethereof is preferably not less than 40.0, more preferably not less than50.0; the tinting strength thereof is preferably not less than 110%,more preferably not less than 115%; the hiding power thereof ispreferably not less than 200 cm²/g, more preferably not less than 400cm²/g; the heat resistance thereof is preferably not less than 180° C.,more preferably not less than 190° C.; the light resistance (ΔE* value)thereof is preferably not more than 5.0, more preferably not more than4.0; the desorption percentage of organic pigments thereof is preferablynot more than 20%, more preferably not more than 15%; and the surfaceactivity thereof is preferably not more than 1.5%, more preferably notmore than 1.0%.

Next, the road marking material containing the color agent for a roadmarking material according to the present invention, is described. Theroad marking material according to the present invention preferably hasan abrasion resistance of not more than 400 mg, a light resistance (ΔE*value) of not more than 5.0, and an aging resistance (ΔE* value) of notmore than 2.5.

Among the road marking materials containing the color agent for a roadmarking material according to the present invention, the cold-appliedpaint-type road marking material defined in JIS K 5665 (first class) hasa contrast ratio of preferably not less than 0.80, more preferably notless than 0.85; an alkali resistance of preferably the rank 4 or 5, morepreferably the rank 5; an abrasion resistance of preferably not morethan 400 mg, more preferably not more than 350 mg; a light resistance(ΔE* value) of preferably not more than 5.0, more preferably not morethan 4.0; and an aging resistance (ΔE* value) of preferably not morethan 2.5, more preferably not more than 2.0. In addition, in the case ofthe yellow-based road marking material, the retroreflective propertythereof is preferably the rank 3 or 4, more preferably the rank 4 whenmeasured by the below-mentioned evaluation method.

Also, among the cold-applied paint-type road marking materials definedin JIS K 5665 (first class), the road marking material containing thecolor agent for a road marking material using inorganic particles coatedwith the intermediate coating material according to the presentinvention can be remarkably improved in light resistance and abrasionresistance to such an extent that the light resistance (ΔE* value)thereof is preferably not more than 4.0, more preferably not more than3.0, and the abrasion resistance thereof is preferably not more than 350mg, more preferably not more than 300 mg.

Further, among the cold-applied paint-type road marking materialsdefined in JIS K 5665 (first class), the road marking materialcontaining the color agent for a road marking material whose surface isfurther coated with the fatty acid, fatty acid metal salt orsilane-based coupling agent, has a contrast ratio of preferably not lessthan 0.80, more preferably not less than 0.85; an alkali resistance ofpreferably the rank 4 or 5, more preferably the rank; a light resistance(ΔE* value) of preferably not more than 5.0, more preferably not morethan 4.0; an aging resistance (ΔE* value) of preferably not more than2.5, more preferably not more than 2.0; and an improved abrasionresistance of preferably not more than 300 mg, more preferably not morethan 250 mg. In addition, in the case of the yellow-based road markingmaterial, the retroreflective property thereof is preferably the rank 3or 4, more preferably the rank 4 when measured by the below-mentionedevaluation method.

Among the road marking materials containing the color agent for a roadmarking material according to the present invention, the heat-appliedpaint-type road marking material defined in JIS K 5665 (second class)has a contrast ratio of preferably not less than 0.80, more preferablynot less than 0.85; an alkali resistance of preferably the rank 4 or 5,more preferably the rank 5; an abrasion resistance of preferably notmore than 350 mg, more preferably not more than 300 mg; a lightresistance (ΔE* value) of preferably not more than 5.0, more preferablynot more than 4.0; and an aging resistance (ΔE* value) of preferably notmore than 2.5, more preferably not more than 2.0. In addition, in thecase of the yellow-based road marking material, the retroreflectiveproperty thereof is preferably the rank 3 or 4, more preferably the rank4 when measured by the below-mentioned evaluation method.

Also, among the heat-applied paint-type road marking materials definedin JIS K 5665 (second class), the road marking material containing thecolor agent for a road marking material using inorganic particles coatedwith the intermediate coating material according to the presentinvention can be improved in light resistance and abrasion resistancesuch that the light resistance (ΔE* value) thereof is preferably notmore than 4.0, more preferably not more than 3.0, and the abrasionresistance thereof is preferably not more than 300 mg, more preferablynot more than 250 mg.

Further, among the heat-applied paint-type road marking materialsdefined in JIS K 5665 (second class), the road marking materialcontaining the color agent for a road marking material whose surface isfurther coated with the fatty acid, fatty acid metal salt orsilane-based coupling agent, has a contrast ratio of preferably not lessthan 0.80, more preferably not less than 0.85; an alkali resistance ofpreferably the rank 4 or 5, more preferably the rank; a light resistance(ΔE* value) of preferably not more than 5.0, more preferably not morethan 4.0; an aging resistance (ΔE* value) of preferably not more than2.5, more preferably not more than 2.0; and an improved abrasionresistance of preferably not more than 250 mg, more preferably not morethan 200 mg. In addition, in the case of the yellow-based road markingmaterial, the retroreflective property thereof is preferably the rank 3or 4, more preferably the rank 4 when measured by the below-mentionedevaluation method.

Among the road marking materials containing the color agent for a roadmarking material according to the present invention, the melt-type roadmarking material defined in JIS K 5665 (third class) has an alkaliresistance of preferably the rank 4 or 5, more preferably the rank 5; anabrasion resistance of preferably not more than 200 mg, more preferablynot more than 180 mg; a light resistance (ΔE* value) of preferably notmore than 5.0, more preferably not more than 4.0; and an agingresistance (ΔE* value) of preferably not more than 2.5, more preferablynot more than 2.0. In addition, in the case of the yellow-based roadmarking material, the retroreflective property thereof is preferably therank 3 or 4, more preferably the rank 4 when measured by thebelow-mentioned evaluation method.

Also, among the melt-type road marking materials defined in JIS K 5665(third class), the road marking material containing the color agent fora road marking material using inorganic particles coated with theintermediate coating material according to the present invention can beimproved in light resistance and abrasion resistance such that the lightresistance (ΔE* value) thereof is preferably not more than 4.0, morepreferably not more than 3.0, and the abrasion resistance thereof ispreferably not more than 180 mg, more preferably not more than 160 mg.

Further, among the melt-type road marking materials defined in JIS K5665 (third class), the road marking material containing the color agentfor a road marking material whose surface is further coated with thefatty acid, fatty acid metal salt or silane-based coupling agent, has analkali resistance of preferably the rank 4 or 5, more preferably therank 5; a light resistance (ΔE* value) of preferably not more than 5.0,more preferably not more than 4.0; an aging resistance (ΔE* value) ofpreferably not more than 2.5, more preferably not more than 2.0; and animproved abrasion resistance of preferably not more than 160 mg, morepreferably not more than 140 mg. In addition, in the case of theyellow-based road marking material, the retroreflective property thereofis preferably the rank 3 or 4, more preferably the rank 4 when measuredby the below-mentioned evaluation method.

In the road marking material of the present invention, the color agentfor a road marking material may be blended in an amount of 0.1 to 60% byweight based on the weight of base materials of the road markingmaterial depending upon the aimed hue of the road marking material. Inparticular, in the case of the paint-type road marking materials definedin JIS K 5665 (first class) and JIS K 5665 (second class), the coloragent for a road marking material may be blended in an amount ofpreferably 5 to 60% by weight based on the total weight of basematerials of the road marking material, and in the case of the melt-typeroad marking material defined in JIS K 5665 (third class), the coloragent for a road marking material may be blended in an amount ofpreferably 0.5 to 30% by weight based on the total weight of basematerials of the road marking material.

The base materials of the road marking material may contain, in additionto the color agent for a road marking material, resins, fillers andvarious additives such as solvents, glass beads (reflecting material)and/or plasticizers, solvents, defoamers, surfactants, assistants or thelike, which may be optionally blended according to types of road markingmaterials, if required. The additives may be blended in an amount ofusually 1 to 10% by weight based on the total weight of the basematerials of the road marking material.

As the resins, there may be used those resins that are generally used inroad marking paints. Examples of the resins may include vegetableoil-modified alkyd resins, urethanated alkyd resins, vinylated alkydresins, vinyl resins, acrylic resins, petroleum resins, rosins andderivatives thereof, terpene resins, polyamide resins, polyester resins,xylene resins, melamine resins, phthalic resins, phenol resins, naturalrubbers, synthetic rubbers, styrene-butadiene copolymer resins,water-soluble acrylic resins, water-soluble maleic resins, water-solublealkyd resins, water-soluble melamine resins, water-soluble urethaneemulsion resins, water-soluble epoxy resins, water-soluble polyesterresins or the like. These resins may be used singly or in the form of amixture of any two or more thereof. The resins may be used in an amountof usually 10 to 30% by weight based on the total weight of the basematerials of the road marking material.

As the fillers, there may be used those fillers that are generally usedin road marking paints. Examples of the fillers may include calciumcarbonate, talc, silica powder, glass beads or the like. The fillers maybe used in an amount of usually 15 to 85% by weight based on the totalweight of the base materials of the road marking material.

As the solvents, there may be used those solvents that are generallyused in road marking paints. Examples of the solvents may includearomatic solvents such as toluene, xylene and thinner; ketone-basedsolvents such as methyl isobutyl ketone, acetone and methyl ethylketone; ester-based solvents such as ethyl acetate, butyl acetate andamyl acetate; alcohol-based solvents such as methyl alcohol, ethylalcohol, propyl alcohol and butyl alcohol; glycol ether-based solventssuch as methyl cellosolve, ethyl cellosolve, propyl cellosolve, butylcellosolve and propylene glycol monomethyl ether; or the like. Thesesolvents may be used singly or in the form of a mixture of any two ormore thereof. The solvents may be used in an amount of usually 10 to 50%by weight based on the total weight of the base materials of the roadmarking material.

Next, the process for producing the color agent for a road markingmaterial according to the present invention is described.

The color agent for a road marking material according to the presentinvention can be produced by first mixing the inorganic particles withthe gluing agent to form a gluing agent coating layer on the surface ofthe inorganic particles, and then mixing the gluing agent-coatedinorganic particles with the organic pigments to form an organic pigmentcoat on the gluing agent coating layer. By uniformly coating the surfaceof the inorganic particles with the gluing agent, the surface activityof the particles can be effectively reduced. Further, in the subsequentorganic pigment-adhering step, the organic pigments can be uniformly andfirmly adhered onto the gluing agent coating layer formed on the surfaceof the inorganic particles.

The formation of the gluing agent coating layer on the surface of theinorganic particle may be conducted by mechanically mixing and stirringthe inorganic particles with the gluing agent or a solution containingthe gluing agent, or by mechanically mixing and stirring the inorganicparticles while spraying the gluing agent or a solution containing thegluing agent thereonto, whereby a substantially whole amount of thegluing agent added is adhered on the surface of the inorganic particles.

Meanwhile, in the case where alkoxysilanes or fluoroalkylsilanes areused as the gluing agent, a part of the alkoxysilanes orfluoroalkylsilanes may be coated in the form of organosilane compoundsobtainable from the alkoxysilanes or fluorine-containing organosilanecompounds obtainable from fluoroalkylsilanes through the coating step.Even in such a case, subsequent adhesion of the organic pigments on thegluing agent-coating layer is not adversely affected.

In order to uniformly coat the gluing agent onto the surface of theinorganic particles, it is preferred that the agglomerated inorganicparticles are previously deaggregated using a crusher.

The mixing and stirring of the inorganic particles with the gluingagent, and the mixing and stirring of the organic pigments with thegluing agent-coated inorganic particles, are preferably carried outusing an apparatus capable of applying a shear force to the powdermixture, especially such an apparatus capable of simultaneouslyeffecting shear action, spatula stroking and compression. Examples ofthe apparatus may include wheel-type kneaders, ball-type kneaders,blade-type kneaders, roll-type kneaders or the like. Among theseapparatuses, the wheel-type kneaders are preferred to effectivelypractice the present invention.

Specific examples of the wheel-type kneaders may include edge runners(similar in meaning to mix muller, Simpson mill and sand mill),multimill, Stotz mill, wet pan mill, corner mill, ring muller or thelike. Among these wheel-type kneaders, the preferred kneaders are edgerunners, multimill, Stotz mill, wet pan mill and ring muller, and themore preferred kneaders are edge runners. Specific examples of theball-type kneaders may include vibration mill or the like. Specificexamples of the blade-type kneaders may include Henschel mixer,planetary mixer, Nauter mixer or the like. Specific examples of theroll-type kneaders may include extruders or the like.

The conditions of the mixing and stirring treatment of the inorganicparticles with the gluing agent may be selected so as to uniformly coatthe surface of the inorganic particles with the gluing agent.Specifically, the mixing and stirring conditions may be appropriatelycontrolled such that the linear load is usually 19.6 to 1,960 N/cm (2 to200 kg/cm), preferably 98 to 1,470 N/cm (10 to 150 kg/cm), morepreferably 147 to 980 N/cm (15 to 100 kg/cm); the treating time isusually 5 minutes to 24 hours, preferably 10 minutes to 20 hours; andthe stirring speed is usually 2 to 2,000 rpm, preferably 5 to 1,000 rpm,more preferably 10 to 800 rpm.

The amount of the gluing agent added is preferably 0.15 to 45 parts byweight based on 100 parts by weight of the inorganic particles. Byadding the gluing agent in an amount of 0.15 to 45 parts by weight, itis possible to adhere 1 to 500 parts by weight of the organic pigmentsonto 100 parts by weight of the inorganic particles through the gluingagent coating layer.

After the surface of the inorganic particles is coated with the gluingagent, the organic pigments are added, and then mixed and stirred withthe gluing agent-coated inorganic particles to adhere the organicpigments onto the gluing agent coating layer. The obtained particles maybe further subjected to drying or heating treatments, if required.

The organic pigments may be added slowly and little by little,especially for a period of 5 minutes to 24 hours, preferably 5 minutesto 20 hours. Alternatively, 5 to 25 parts by weight of the organicpigments may be intermittently added to 100 parts by weight of theinorganic particles until the amount of the organic pigments addedreaches the desired value.

Also, when a plurality of organic pigments are used for adjusting thehue, it is preferred that each kind of organic pigments used may beseparately added and adhered onto the surface of the inorganicparticles. If the plurality of organic pigments are added at the sametime, there may be caused undesired adhesion of the particles to aninside of the mixing apparatus, so that it may be difficult toindustrially produce treated particles having a uniform hue.

The mixing and stirring conditions of the gluing agent coated inorganicparticles with organic pigments may be appropriately selected so as toform a uniform organic pigment coat on the gluing agent coating layer,and may be controlled such that the linear load is usually 19.6 to 1,960N/cm (2 to 200 kg/cm), preferably 98 to 1,470 N/cm (10 to 150 kg/cm),more preferably 147 to 980 N/cm (15 to 100 kg/cm); the treating time isusually 5 minutes to 24 hours, preferably 10 minutes to 20 hours; andthe stirring speed is usually 2 to 2,000 rpm, preferably 5 to 1,000 rpm,more preferably 10 to 800 rpm.

The amount of the organic pigments added is usually 1 to 500 parts byweight, preferably 5 to 400 parts by weight, more preferably 10 to 300parts by weight based on 100 parts by weight of the inorganic particles.

In the color agent for a road marking material according to the presentinvention, the organic pigments added are finely divided in the abovetreating steps to form a uniform and dense adhesion layer composed ofthe organic pigments on the surface of the inorganic particles throughthe gluing agent coating layer.

The heating temperature used in the drying and heating treatments ispreferably 40 to 150° C., more preferably 60 to 120° C., and the heatingtime is preferably 10 minutes to 12 hours, more preferably 30 minutes to3 hours.

Meanwhile, in the case where alkoxysilanes or fluoroalkylsilanes areused as the gluing agent, the alkoxysilanes or fluoroalkylsilanes arefinally coated in the form of organosilane compounds obtainable from thealkoxysilanes or fluorine-containing organosilane compounds obtainablefrom the fluoroalkylsilanes through these steps.

The color agent for a road marking material which has a plurality ofcoloring adhesion layers, may be produced by mixing the inorganicparticles with the gluing agent to form a gluing agent coating layer onthe surface of the inorganic particles; mixing the organic pigments withthe gluing agent-coated inorganic particles to adhere the organicpigments onto the gluing agent coating layer, thereby forming a firstcoloring adhesion layer (to obtain intermediate particles); then mixingthe thus obtained intermediate particles having the first coloringadhesion layer with the gluing agent; and then further mixing theobtained gluing agent-coated intermediate particles with the organicpigments to form a second coloring adhesion layer onto the second gluingagent coating layer formed on the intermediate particles. The mixingtreatment with the gluing agent and the mixing treatment with theorganic pigments in each of the above steps may be conducted by the samemethod as described previously. Meanwhile, by repeating the coating withthe gluing agent and the adhesion of the organic pigments according torequirements, it is possible to obtain such a color agent for a roadmarking material having three or more coloring adhesion layers thereon.

The inorganic particles may be coated, if required, with at least oneintermediate coating material selected from the group consisting ofhydroxides of aluminum, oxides of aluminum, hydroxides of silicon, andoxides of silicon prior to mixing and stirring step with the gluingagent.

The coating with the intermediate coating material is conducted asfollows. That is, an aluminum compound, a silicon compound or both thealuminum and silicon compounds are added to a water suspension preparedby dispersing the inorganic particles in water. The resultant dispersionis mixed and stirred together and then, if required, the pH valuethereof is adjusted adequately, thereby coating at least oneintermediate coating material selected from the group consisting ofhydroxides of aluminum, oxides of aluminum, hydroxides of silicon, andoxides of silicon, on the surface of the inorganic particles.Thereafter, the thus-obtained inorganic particles coated with theintermediate coating material are filtered out, washed with water, driedand then pulverized, and may be further subjected to subsequenttreatments such as deaeration and compaction, if required.

Examples of the aluminum compound may include aluminum salts such asaluminum acetate, aluminum sulfate, aluminum chloride and aluminumnitrate, alkali aluminates such as sodium aluminate, or the like.

Examples of the silicon compound may include water glass #3, sodiumorthosilicate, sodium metasilicate or the like.

The color agent for a road marking material according to the presentinvention may also be produced by coating the above-obtained color agentto be coated with a fatty acid, a fatty acid metal salt or asilane-based coupling agent.

The coating of the color agent to be coated with the fatty acid, fattyacid metal salt or silane-based coupling agent may be conducted bymechanically mixing and stirring the color agent to be coated with thefatty acid, fatty acid metal salt or silane-based coupling agent whileheating.

The amount of the fatty acid, fatty acid metal salt or silane-basedcoupling agent coated is preferably 0.13 to 67 parts by weight based on100 parts by weight of the color agent to be coated therewith. When thefatty acid, fatty acid metal salt or silane-based coupling agent iscoated in an amount of 0.13 to 67 parts by weight, it is possible toreduce the surface activity of the obtained color agent for a roadmarking material and enhance the abrasion resistance of the road markingmaterial obtained using such a color agent.

The heating temperature used in the above step of coating the coloragent to be coated with the fatty acid, fatty acid metal salt orsilane-based coupling agent, is preferably not less than 40° C., morepreferably not less than 50° C., most preferably not less than 60° C.,and the upper limit of the heating temperature is 150° C. or a meltingor boiling point of the fatty acid, fatty acid metal salt orsilane-based coupling agent.

The point of the present invention is that the road marking materialcontaining the color agent which comprises the inorganic particles, thegluing agent coating layer formed on the surface of the inorganicparticles and the organic pigment coat formed on the gluing agentcoating layer, are substantially free from the change in hue with thepassage of time, and can exhibit an excellent retroreflective property.

The reason why the color agent for a road marking material according tothe present invention can be inhibited from undergoing the change in huewith the passage of time, is considered by the present inventors asfollows.

That is, it is considered that the change in hue of the road markingmaterial is caused by discoloration of color pigments and deteriorationof resins due to ultraviolet radiation, acid rain, etc., as well asdeterioration of resins due to the high surface activity of the colorpigments. On the contrary, in the color agent for a road markingmaterial according to the present invention, by coating the surface ofthe inorganic particles having a higher light resistance than that ofthe organic pigments, with the gluing agent, and adhering the organicpigments thereon through the gluing agent coating layer, the obtainedparticles can show a more excellent light resistance than that of theorganic pigments solely. Further, by coating the surface of theinorganic particles having a high surface activity, with the gluingagent, and adhering the organic pigments thereon through the gluingagent coating layer, the surface activity of the obtained particles canbe considerably reduced. As a result, it is considered that the roadmarking material containing the color agent for a road marking materialaccording to the present invention can be inhibited from undergoing thechange in hue with the passage of time due to the synergistic effect ofthe improved light resistance and reduced surface activity of the coloragent.

In particular, in the case where the yellow-based organic pigments areadhered, it is possible to obtain a color agent for a road markingmaterial showing a high retroreflective property. Further, in the casewhere the yellow-based organic pigments are adhered onto the surface ofthe inorganic particles containing at least titanium oxide particles, itis possible to obtain a color agent for a road marking material which isexcellent in not only retroreflective property but also contrast ratio.

The color agent for a road marking material according to the presentinvention is excellent in tinting strength, hiding power, lightresistance and heat resistance and suppressed in surface activity, andfurther is harmless. Therefore, the color agent of the present inventionis suitable as a color agent for a road marking material.

The road marking material of the present invention using the above coloragent for a road marking material can be inhibited from undergoing thechange in hue with the passage of time, and can show an excellentretroreflective property and, therefore, is suitable as a road markingmaterial that is free from environmental pollution.

EXAMPLES

The present invention will now be described in more detail withreference to the following examples, but the present invention is notrestricted to those examples and various modifications are possiblewithin the scope of the present invention.

Various properties were evaluated by the following methods.

(1) The average particle diameter of the particles was expressed by anaverage value of diameters of 350 particles observed on a micrograph.

(2) The specific surface area was expressed by the value measured by aBET method.

(3) The amounts of Al and Si which were present on the surface ofinorganic particles coated with an intermediate coating material, wererespectively measured by a fluorescent X-ray spectroscopy device “3063M-type” (manufactured by RIGAKU DENKI KOGYO CO., LTD.) according to JISK0119 “General rule of fluorescent X-ray analysis”.

(4) The amount of the gluing agent coated on the surface of theinorganic particles, the amount of the organic pigments adhered onto thecolor agent for a road marking material, and the amount of the fattyacid, fatty acid metal salt or silane-based coupling agent coated on thecolor agent to be coated, were respectively expressed by the amount ofcarbon measured by “Horiba Metal, Carbon and Sulfur Analyzer EMIA-2200Model” (manufactured by HORIBA SEISAKUSHO CO., LTD.).

(5) The hues of the inorganic particles, organic pigments and coloragent for a road marking material, were respectively measured by thefollowing method.

That is, 0.5 g of each sample and 0.5 ml of castor oil were intimatelykneaded together by a Hoover's muller to form a paste. 4.5 g of clearlacquer was added to the obtained paste and was intimately kneaded toform a paint. The obtained paint was applied on a cast-coated paper byusing a 150 μm (6-mil) applicator to produce a coating film piece(having a film thickness of about 30 μm). The thus obtained coating filmpiece was measured by a spectrocolorimeter “CM-3610d” (manufactured byMINOLTA CO., LTD.) and expressed by color specification values accordingto JIS Z 8929. Meanwhile, the C* value representing chroma is calculatedaccording to the following formula:C*=((a*)²+(b*)²)^(1/2)

(6) The tinting strength of the color agent for a road marking materialwas measured by the following method.

That is, a primary color enamel and a vehicle enamel prepared by thebelow-mentioned method were respectively applied on a cast-coated paperby a 150 μm (6-mil) applicator to produce coating film pieces. The thusobtained coating film pieces were measured by a spectrocolorimeter“CM-3610d” (manufactured by MINOLTA CO., LTD.) to determine L* valuesthereof. The difference between the obtained L* values was representedby a ΔL* value.

Next, as a standard sample for the color agent for a road markingmaterial, a mixed pigment was prepared by simply mixing the organicpigments and the inorganic particles at the same mixing ratio as usedfor the production of the color agent for a road marking material. Usingthe thus prepared mixed pigment as standard sample, the same procedureas defined above was conducted to prepare an primary color enamel and avehicle enamel, form coating film pieces and measure L* values thereof.The difference between the L* values was represented by a ΔLs* value.

From the obtained ΔL* value of the color agent for a road markingmaterial and ΔLs* value of the standard sample, the tinting strength (%)was calculated according to the following formula:Tinting strength (%)=100+{(ΔLs*−ΔL*)×10}Preparation of Primary Color Enamel:

10 g of the above sample particles, 16 g of an amino alkyd resin and 6 gof a thinner were blended together. The resultant mixture was addedtogether with 90 g of 3 mmφ glass beads into a 140-ml glass bottle, andthen mixed and dispersed for 45 minutes by a paint shaker. The obtainedmixture was further mixed with 50 g of an amino alkyd resin, anddispersed for 5 minutes by a paint shaker, thereby obtaining an primarycolor enamel.

Preparation of Vehicle Enamel:

12 g of the above-prepared primary color enamel and 40 g of Aramic White(titanium dioxide-dispersed amino alkyd resin) were blended together,and the resultant mixture was mixed and dispersed for 15 minutes by apaint shaker, thereby preparing a vehicle enamel.

(7) The hiding powers of the inorganic particles and color agent for aroad marking material were measured by the cryptometer method accordingto JIS K5101-8.2 using the above-prepared primary color enamel.

(8) The light resistances of the inorganic particles, organic pigmentsand color agent for a road marking material were measured by thefollowing method.

That is, the same primary color enamel as prepared above for themeasurement of tinting strength, was applied at a thickness of 150 μmonto a cold-rolled steel plate (0.8 mm×70 mm×150 mm; JIS G-3141) anddried to form a coating film. One half of the thus prepared testspecimen was covered with a metal foil, and an ultraviolet light wascontinuously irradiated over the test specimen at an intensity of 100mW/cm² for 6 hours using “EYE SUPER UV TESTER SUTV-W13” (manufactured byIWASAKI DENKI CO., LTD.). Then, the hues (L*, a* and b* values) of themetal foil-covered non-irradiated portion and the UV-irradiated portionof the test specimen were respectively measured. The ΔE* value wascalculated from differences between the measured hue values of the metalfoil-covered non-irradiated portion and the UV-irradiated portionaccording to the following formula:ΔE*=[(ΔL*)²+(Δa*)²+(Δb*)²]^(1/2)wherein ΔL* represents the difference between L* values of thenon-irradiated and UV-irradiated portions; Δa* represents the differencebetween a* values of the non-irradiated and UV-irradiated portions; andΔb* represents the difference between b* values of the non-irradiatedand UV-irradiated portions.

(9) The surface activity of the color agent for a road marking materialwas evaluated by measuring the amount of residual solvent by thefollowing method.

First, 1 g of sample particles and 10 g of a solvent (MEK) were weighed.Then, the sample particles were immersed in the solvent for 3 hours,air-dried for 24 hours and further dried at 60° C. for 24 hours. Theamount of carbon contained in the thus dried sample particles wasmeasured using “Horiba Metal, Carbon and Sulfur Analyzer EMIA-2200Model” (manufactured by HORIBA SEISAKUSHO CO., LTD.) to determine theamount of residual carbon therein. The smaller amount of the residualcarbon represents the smaller amount of the residual solvent containedin the particles, namely a less surface activity of the particles.

(10) The heat resistance of the color agent for a road marking materialwas expressed by the temperature which was read at a crossing point oftwo tangential lines respectively drawn on two curves constituting thefirst one of two inflection points which form a peak on a DSC chartprepared by subjecting the color agent to differential scanningcalorimetry (DSC) using a thermal analyzer “SSC-5000” (manufactured bySEIKO DENSHI KOGYO CO., LTD.).

(11) The desorption percentage (%) of the organic pigments desorbed fromthe color agent for a road marking material was measured by thefollowing method. The closer to 0% the desorption percentage, thesmaller the amount of the organic pigments desorbed from the surface ofparticles of the color agent for a road marking material.

That is, 3 g of the particles to be measured and 40 ml of ethanol wereplaced in a 50-ml precipitation tube and then subjected to ultrasonicdispersion for 20 minutes. Thereafter, the obtained dispersion wasallowed to stand for 120 minutes to separate the desorbed organicpigments from the particles on the basis of the difference in specificgravity between the organic pigments and the particles. Next, theparticles were mixed again with 40 ml of ethanol and then subjected toultrasonic dispersion for 20 minutes. Thereafter, the obtaineddispersion was allowed to stand for 120 minutes to separate the desorbedorganic pigments from the particles. The thus separated particles weredried at 100° C. for one hour, and the amount of carbon contained in theparticles was measured by “Horiba Metal, Carbon and Sulfur AnalyzerEMIA-2200 Model” (manufactured by HORIBA SEISAKUSHO CO., LTD.). Thedesorption percentage (%) of the organic pigments was calculatedaccording to the following formula:Desorption percentage of organic pigments (%)={(W _(a) −W _(e))/W_(a)}×100wherein W_(a) represents an amount of organic pigments initially adheredonto the color agent for a road marking material; and W_(e) representsan amount of organic pigments still adhered on the color agent for aroad marking material after desorption test.

(12) The contrast ratio of the road marking material was measured by thefollowing method.

That is, a test specimen was prepared using each paint produced by thebelow-mentioned method according to JIS K 5665. The tristimulus valuesof the thus prepared test specimen were measured by a reflectometeraccording to JIS Z8722 to calculate the contrast ratio from the measuredvalues.

(13) The alkali resistance of the road marking material was evaluated bythe following method.

That is, a test specimen was produced using each paint prepared by thebelow-mentioned method, and evaluated according to JIS K 5665. Further,the hues (L*, a* and b* values) thereof before and after the immersionin an aqueous alkali solution were respectively measured. The ΔE* valuewas calculated from the difference between the hue values before andafter the immersion in an aqueous alkali solution according to thefollowing formula:ΔE*=[(ΔL*)²+(Δa*)²+(Δb*)²]^(1/2)wherein ΔL* represents the difference between L* values of the testspecimen before and after the alkali immersion treatment; Δa* representsthe difference between a* values of the test specimen before and afterthe alkali immersion treatment; and Δb* represents the differencebetween b* values of the test specimen before and after the alkaliimmersion treatment.

Using the thus obtained ΔE* value, the alkali resistance of the roadmarking material was evaluated on the basis of the following five ranks.

-   -   Rank 5: Test specimen was free from swells, cracks, peelings and        pinholes, and ΔE* value thereof was not more than 3.0;    -   Rank 4: Test specimen was free from swells, cracks, peelings and        pinholes, and ΔE* value thereof was not more than 4.0;    -   Rank 3: Test specimen was free from swells, cracks, peelings and        pinholes, and ΔE* value thereof was not more than 5.0;    -   Rank 2: Test specimen was free from swells, cracks, peelings and        pinholes, and ΔE* value thereof was more than 5.0; and    -   Rank 1: Test specimen suffered from swells, cracks, peelings and        pinholes.

(14) The abrasion resistance of the road marking material was measuredas follows. That is, a test specimen was produced using each paintprepared by the below-mentioned method. The abrasion resistance of thethus produced test specimen was measured according to JIS K 5665.

(15) The light resistance of the road marking material was measured bythe following method.

That is, one half of a test specimen produced by coating each paintprepared by the below-mentioned method on a glass plate (about 200×100×2mm), was covered with a metal foil, and an ultraviolet light wascontinuously irradiated over the test specimen at an intensity of 100mW/cm² for 6 hours using “EYE SUPER UV TESTER (SUV-W13)” (manufacturedby IWASAKI DENKI CO., LTD.). Then, the hues (L*, a* and b* values) ofthe metal foil-covered non-irradiated portion and the UV-irradiatedportion of the test specimen were respectively measured. The ΔE* valuewas calculated from the difference between the measured hue values ofthe metal foil-covered non-irradiated portion and the UV-irradiatedportion according to the above-described formula.

(16) The aging resistance of the road marking material was measured bythe following method.

That is, a test specimen was produced by coating each paint prepared bythe below-mentioned method on a glass plate (about 200×100×2 mm), andallowed to stand under environmental conditions having a temperature of60° C. and a relative humidity of 90% for one month. The hues (L*, a*and b* values) of the test specimen before and after the aging test weremeasured. The aging resistance of the test specimen was represented bythe ΔE* value calculated from the difference between the measured huevalues according to the following formulaΔE*=[(ΔL*)²+(Δa*)²+(Δb*)²]^(1/2)wherein ΔL* represents the difference between L* values before and afterthe aging test; Δa* represents the difference between a* values beforeand after the aging test; and Δb* represents the difference between b*values before and after the aging test.

(17) The retroreflective property of the road marking material wasevaluated by the following method.

That is, a test specimen was produced by coating each paint prepared bythe below-mentioned method on a glass plate (about 200×100×2 mm). Thethus produced test specimen was placed on a black cloth within a darkroom, and irradiated with a light at an angle of about 300 from a 30Wfluorescent lamp disposed at a distance of 2 m from the test specimen.The retroreflective property of the test specimen was evaluated on thebasis of the following four ranks.

-   -   Rank 4: Sufficient retroreflective property (yellowish);    -   Rank 3: Some retroreflective property (slightly whitish);    -   Rank 2: Slight retroreflective property (whitish); and    -   Rank 1: No retroreflective property (white).

Example 1

<Production of Color Agent for a Road Marking Material>

20 kg of titanium oxide particles (particle shape: granular shape;average particle diameter: 0.238 μm; BET specific surface area value:11.6 m²/g; L* value: 96.31, a* value: 1.06, b* value: −1.66 and C*value: 1.97; hiding power: 1,490 cm²/g; refractive index: 2.71; lightresistance (ΔE* value): 6.86) were deaggregated in 150 liters of purewater using a stirrer, and further passed through a TK pipelinehomomixer (manufactured by TOKUSHU KIKA KOGYO CO., LTD.) three times,thereby obtaining a slurry containing the titanium oxide particles.

Successively, the obtained slurry containing the titanium oxideparticles was passed through a transverse-type sand grinder (tradename“MIGHTY MILL MHG-1.5L”, manufactured by INOUE SEISAKUSHO CO., LTD.) fivetimes at an axis-rotating speed of 2,000 rpm, thereby obtaining a slurryin which the titanium oxide particles were dispersed.

The titanium oxide particles in the obtained slurry, which remained on asieve of 325 meshes (mesh size: 44 μm) was 0%. The slurry was filteredand washed with water, thereby obtaining a wet cake composed of thetitanium oxide particles. The obtained wet cake composed of the titaniumoxide particles was dried at 120° C. 11.0 kg of the dried particles werethen charged into an edge runner (tradename “MPUV-2 Model”, manufacturedby MATSUMOTO CHUZO TEKKOSHO CO., LTD.), and mixed and stirred at 294N/cm (30 Kg/cm) for 30 minutes, thereby lightly deaggregating theparticles.

Then, 110 g of methyltriethoxysilane (tradename “TSL8123” produced by GETOSHIBA SILICONE CO., LTD.) was added to the deaggregated titanium oxideparticles while operating the edge runner. The titanium oxide particleswere continuously mixed and stirred at a linear load of 588 N/cm (60Kg/cm) and a stirring speed of 22 rpm for 30 minutes.

Next, 4,400 g of organic pigments Y-1 (kind: disazo-based organic yellowpigments; particle shape: granular shape; average particle diameter:0.15 μm; BET specific surface area value: 41.7 m²/g; L* value: 69.51, a*value: 38.31 and b* value: 76.96; light resistance (ΔE* value): 18.25)were added to the titanium oxide particles coated withmethyltriethoxysilane for 10 minutes while operating the edge runner.Further, the particles were continuously mixed and stirred at a linearload of 392 N/cm (40 Kg/cm) and a stirring speed of 22 rpm for 30minutes. Successively, 110 g of organic pigments R-1 (kind: condensedpolycyclic-type organic red pigments; particle shape: granular shape;average particle diameter: 0.10 μm; BET specific surface area value:89.8 m²/g; L* value: 37.81, a* value: 44.03 and b* value: 24.09; lightresistance (ΔE* value): 15.47) were added to the above-obtainedparticles for 10 minutes while operating the edge runner. Further, theresultant particles were continuously mixed and stirred at a linear loadof 392 N/cm (40 Kg/cm) and a stirring speed of 22 rpm for 20 minutes,thereby successively adhering the organic pigments Y-1 and R-1 on thecoating layer composed of methyltriethoxysilane. Then, the thus obtainedcoated particles were heat-treated at 105° C. for 60 minutes by using adrier, thereby obtaining composite particles.

The color agent for a road marking material composed of the thusobtained composite particles was in the form of granular particleshaving an average particle diameter of 0.240 μm. In addition, the coloragent for a road marking material showed a BET specific surface areavalue of 16.4 m²/g, a lightness (L* value) of 68.59, a tinting strengthof 137%, a hiding power of 1,405 cm²/g, a surface activity of 1.14%, aheat resistance of 235° C. and a light resistance (ΔE* value) of 2.41.The desorption percentage of the organic pigments from the color agentfor a road marking material was 7.4%. The amount of a coatingorganosilane compounds produced from methyltriethoxysilane was 0.07% byweight (calculated as C), and the amount of the organic pigment coatformed on the coating layer composed of the organosilane compoundsproduced from methyltriethoxysilane was 16.52% by weight (calculated asC) (the total amount of the organic pigments Y-1 and R-1 adheredcorresponded to 41 parts by weight based on 100 parts by weight of thetitanium oxide particles).

As a result of observing the micrograph, since no organic pigments wasrecognized from the micrograph, it was confirmed that a substantiallywhole amount of the organic pigments added contributed to the formationof the organic pigment coat on the coating layer composed of theorganosilane compounds produced from methyltriethoxysilane.

<Production of Road Marking Paint (First Class) Containing Color Agentfor a Road Marking Material>

Base materials for road marking paint including the color agent for aroad marking material were blended with each other at the followingmixing ratio, and kneaded together using a ball mill, thereby obtaininga road marking paint (first class).

Composition:

Color agent for a road marking material 15.0 parts by weight Amino alkydresin 16.0 parts by weight Additives  3.0 parts by weight Solvent(toluene) 35.0 parts by weight Heavy calcium carbonate 15.0 parts byweight Talc 16.0 parts by weight

A test specimen was prepared using the thus obtained road marking paint,and subjected to various tests.

As a result, it was confirmed that the obtained road marking materialhad a contrast ratio of 0.97, an alkali resistance of the rank 5, anabrasion resistance of 310 mg, a light resistance (ΔE* value) of 3.19,an aging resistance (ΔE* value) of 1.94 and a retroreflective propertyof the rank 4.

<Production of Road Marking Paint (Second Class) Containing Color Agentfor a Road Marking Material>

Base materials for road marking paint including the color agent for aroad marking material were blended with each other at the followingmixing ratio, and kneaded together using a ball mill, thereby obtaininga road marking paint (second class).

Composition:

Color agent for a road marking material 15.0 parts by weight Amino alkydresin 16.0 parts by weight Additives  3.0 parts by weight Solvent(toluene) 25.0 parts by weight Heavy calcium carbonate 16.0 parts byweight Talc 25.0 parts by weight

A test specimen was prepared using the thus obtained road marking paint,and subjected to various tests.

As a result, it was confirmed that the obtained road marking materialhad a contrast ratio of 0.98, an alkali resistance of the rank 5, anabrasion resistance of 277 mg, a light resistance (ΔE* value) of 3.16,an aging resistance (ΔE* value) of 1.92 and a retroreflective propertyof the rank 4.

<Production of Road Marking Paint (Third Class) Containing Color Agentfor a Road Marking Material>

Base materials for road marking paint including the color agent for aroad marking material were blended with each other at the followingmixing ratio, and heat-kneaded together at a temperature of 160 to 190°C., thereby obtaining a road marking paint (third class).

Composition:

Color agent for a road marking material  5.0 parts by weight Petroleumresin 12.0 parts by weight Rosin-modified maleic resin  6.0 parts byweight Plasticizer  3.0 parts by weight Glass beads 16.0 parts by weightHeavy calcium carbonate 38.0 parts by weight Crystalline limestone(Kansuiseki) 20.0 parts by weight

A test specimen was prepared using the thus obtained road marking paint,and subjected to various tests.

As a result, it was confirmed that the obtained road marking materialhad an alkali resistance of the rank 5, an abrasion resistance of 145mg, a light resistance (ΔE* value) of 3.01, an aging resistance (ΔE*value) of 1.89 and a retroreflective property of the rank 4.

Core Particles 1 to 7:

Inorganic particles as core particles 1 to 7 having properties shown inTable 1 were prepared.

Core Particles 8:

A slurry containing titanium oxide particles was obtained by dispersing20 kg of titanium oxide particles (core particles 1) in 150 liters ofwater. The pH value of the thus obtained re-dispersed slurry containingthe titanium oxide particles was adjusted to 10.5 by using an aqueoussodium hydroxide solution, and then the concentration of the solids inthe slurry was adjusted to 98 g/liter by adding water thereto. After 150liters of the slurry was heated to 60° C., 5,444 ml of a 1.0 mol/litersodium aluminate solution (corresponding to 1.0% by weight (calculatedas Al) based on the weight of the titanium oxide particles) was added tothe slurry. After allowing the obtained slurry to stand for 30 minutes,the pH value of the slurry was adjusted to 7.5 by using acetic acid.After further allowing the resultant slurry to stand for 30 minutes, theslurry was subjected to filtration, washing with water, drying andpulverization, thereby obtaining the titanium oxide particles whosesurface was coated with hydroxides of aluminum.

The essential production conditions are shown in Table 2, and variousproperties of the obtained surface-treated titanium oxide particles areshown in Table 3.

Core Particles 9 to 14:

The same procedure as defined for the production of the above coreparticles 8, was conducted except that the core particles 2 to 7 wererespectively used instead of the core particles 1, and kinds and amountsof coating materials were changed variously, thereby obtaining inorganicparticles whose surface was coated with the coating material.

The essential production conditions are shown in Table 2, and variousproperties of the obtained surface-treated inorganic particles are shownin Table 3.

Meanwhile, in Tables, “A” and “S” as described in “kind of coatingmaterial used in surface-treating step” represent hydroxides of aluminumand oxides of silicon, respectively.

Organic Pigments:

Organic pigments having properties as shown in Table 4 were prepared.

Examples 2 to 17 and Comparative Examples 1 and 2

The same procedure as defined in Example 1 was conducted except thatkinds and amounts of gluing agents added in coating step with gluingagent, linear load and treating time for edge runner treatment used inthe coating step with gluing agent, kinds and amounts of organicpigments adhered in organic pigment-adhering step, and linear load andtreating time for edge runner treatment used in the organicpigment-adhering step, were changed variously, thereby obtaining coloragents for road marking material.

The essential production conditions are shown in Table 5, and variousproperties of the obtained color agents for road marking material areshown in Table 6.

Meanwhile, in Example 4, 100.0 parts by weight of the core particleswere first mixed with 20.0 parts by weight of the organic pigments Y-2and then with 0.6 part by weight of the organic pigments R-1 whileoperating the edge runner. In Example 5, the organic pigments Y-1 wasadded six times in an amount of 25.0 parts by weight each such that thetotal amount of the organic pigment Y-1 added was 150.0 parts by weightbased on 100 parts by weight of the core particles. In Example 6, 100.0parts by weight of the organic pigment R-1 were continuously added to100.0 parts by weight of the core particles for 100 minutes. In Example9, 100 parts by weight of the core particles were first mixed with 60.0parts by weight of the organic pigments Y-1 and then with 1.5 parts byweight of the organic pigments R-2 while operating the edge runner.

Further, in Example 16, mixed particles containing 57.5 parts by weightof the core particles 1, 17.7 parts by weight of the core particles 4and 24.8 parts by weight of the core particles 5 were used as the coreparticles. In Example 17, mixed particles containing 50.0 parts byweight of the core particles 5 and 50.0 parts by weight of the coreparticles 8 were used as the core particles.

Comparative Example 3

Follow-up Test of Example 1 of Japanese Patent Application Laid-Open(KOKAI) No. 4-132770(1992):

0.066 mol of acetoaceto-2,5-dimethoxy-chloroanilide was dissolved in 300ml of water using an equimolar amount of sodium hydroxide so as toadjust the total amount of the resultant solution to 500 ml. 24.5 g oftitanium oxide particles (core particles 1) were added to the solutionwhile stirring, and then 100 ml of 0.15 mol acetic acid was dropped intothe solution, thereby preparing a coupler solution. Successively, 250 mlof a tetrazolated solution containing 0.03 mol of 3,3-dichlorobenzidinewas dropped into the coupler solution for about 2 hours. Aftercompletion of the dropping, the resultant solution was heated to 90° C.,and continuously stirred for 60 minutes. Then, the obtained solution wasfiltered, washed with water and dried at 90° C., thereby obtainingcomposite particles. It was confirmed that the thus produced organicpigments were disazo-based pigments (C. I. Pigment Yellow 83), and thecomposite particles were composed of the inorganic pigments and organicpigments at a ratio of 1:1.

Comparative Example 4

Follow-up Test of Example 2 of Japanese Patent Application Laid-Open(KOKAI) No. 7-331113(1995):

Respective raw materials shown below were blended with each other at thefollowing mixing ratio using a High-speed mixer, thereby producing apigment composition. Specifically, the raw materials were stirred andmixed together under room temperature condition at an axis-rotatingspeed of 1,000 rpm for 45 minutes, and then the obtained pigmentcomposition was taken out of the mixer.

Composition of Raw Materials:

Organic pigments Y-2 (condensed polycyclic-type 41.0 parts by weightyellow pigments) Organic pigments R-1 (condensed polycyclic-type  1.5parts by weight red pigments) Core particles 1 (titanium oxide) 32.5parts by weight Core particles 4 (calcium carbonate) 10.0 parts byweight Core particles 5 (precipitated barium sulfate) 14.0 parts byweight Silane-based coupling agent  1.0 part by weight

Various properties of the color agents obtained in Comparative Examples3 and 4 are shown in Table 6.

Example 18

<Color Agent for a Road Marking Material Having a Plurality of ColoringAdhesion Layers>

20 kg of titanium oxide particles (core particles 1) were deaggregatedin 150 liters of pure water using a stirrer, and further passed througha TK pipeline homomixer (manufactured by TOKUSHU KIKA KOGYO CO., LTD.)three times, thereby obtaining a slurry containing the titanium oxideparticles.

Successively, the obtained slurry containing the titanium oxideparticles was passed through a transverse-type sand grinder (tradename“MIGHTY MILL MHG-1.5L”, manufactured by INOUE SEISAKUSHO CO., LTD.) fivetimes at an axis-rotating speed of 2,000 rpm, thereby obtaining a slurryin which the titanium oxide particles were dispersed.

The titanium oxide particles in the obtained slurry, which remained on asieve of 325 meshes (mesh size: 44 μm) was 0%. The slurry was filteredand washed with water, thereby obtaining a wet cake composed of thetitanium oxide particles. The obtained wet cake composed of the titaniumoxide particles was dried at 120° C. 11.0 kg of the dried particles werethen charged into an edge runner (tradename “MPUV-2 Model”, manufacturedby MATSUMOTO CHUZO TEKKOSHO CO., LTD.), and mixed and stirred at 294N/cm (30 Kg/cm) for 30 minutes, thereby lightly deaggregating theparticles.

Then, 220 g of methylhydrogenpolysiloxane (tradename “TSF484” producedby GE TOSHIBA SILICONE CO., LTD.) was added to the deaggregated titaniumoxide particles while operating the edge runner. The titanium oxideparticles were continuously mixed and stirred at a linear load of 588N/cm (60 Kg/cm) and a stirring speed of 22 rpm for 20 minutes.

Next, 5,500 g of the organic pigments Y-1 were added to the titaniumoxide particles coated with methylhydrogenpolysiloxane for 20 minuteswhile operating the edge runner. Further, the particles werecontinuously mixed and stirred at a linear load of 588 N/cm (60 Kg/cm)and a stirring speed of 22 rpm for 30 minutes, thereby obtainingintermediate particles 1 having an organic pigment coat composed of theorganic pigments Y-1 which was adhered onto the coating layer composedof methylhydrogenpolysiloxane.

In order to determine the amount of the coating layer composed ofmethylhydrogenpolysiloxane and the amount of the organic pigments Y-1adhered thereonto, a part of the obtained intermediate particles 1 weresampled, and heat-treated at 105° C. for 60 minutes using a dryer. As aresult, it was confirmed that the amount of the coating layer composedof methylhydrogenpolysiloxane was 0.53% by weight (calculated as C), andthe amount of the organic pigments Y-1 adhered thereonto was 19.08% byweight (calculated as C; corresponding to 50 parts by weight based on100 parts by weight of the titanium oxide particles). As a result ofobserving the micrograph, since no organic pigments Y-1 were recognizedfrom the micrograph, it was confirmed that a substantially whole amountof the organic pigments Y-1 added contributed to the formation of theorganic pigment coat on the coating layer composed ofmethylhydrogenpolysiloxane.

Then, 220 g of dimethylpolysiloxane (tradename “TSF451” produced by GETOSHIBA SILICONE CO., LTD.) was added to the intermediate particles 1while operating the edge runner. The particles were continuously mixedand stirred at a linear load of 588 N/cm (60 Kg/cm) and a stirring speedof 22 rpm for 30 minutes, thereby obtaining the intermediate particles 1whose surface was coated with a coating layer composed ofdimethylpolysiloxane.

Next, 165 g of the organic pigments R-1 were added to the resultantparticles for 20 minutes while operating the edge runner. Further, theparticles were continuously mixed and stirred at a linear load of 294N/cm (30 Kg/cm) and a stirring speed of 22 rpm for 20 minutes, therebyadhering the organic pigments R-1 onto the adhesion layer composed ofthe organic pigments Y-1 through the coating layer composed ofdimethylpolysiloxane. Thereafter, the thus obtained composite particleswere heat-treated at 105° C. for 60 minutes, thereby obtaining a coloragent for a road marking material.

As a result of observing the micrograph, since no organic pigments R-1were recognized from the micrograph, it was confirmed that asubstantially whole amount of the organic pigments R-1 added contributedto the formation of the organic pigment coat on the coating layercomposed of dimethylpolysiloxane.

The essential production conditions are shown in Tables 7 and 8, andvarious properties of the obtained color agents for road markingmaterial in the form of composite particles are shown in Table 9.

Examples 19 to 24

The same procedure as defined in Example 18 was conducted except thatkinds of core particles used upon formation of the first coloringadhesion layer, kinds and amounts of gluing agents added in gluingagent-coating step upon formation of the first coloring adhesion layer,linear load and treating time for edge runner treatment used in thegluing agent-coating step upon formation of the first coloring adhesionlayer, kinds and amounts of organic pigments adhered in organicpigment-adhering step upon formation of the first coloring adhesionlayer, and linear load and treating time for edge runner treatment usedin the organic pigment-adhering step upon formation of the firstcoloring adhesion layer, as well as kinds of intermediate particles usedupon formation of the second coloring adhesion layer, kinds and amountsof gluing agents added in gluing agent-coating step upon formation ofthe second coloring adhesion layer, linear load and treating time foredge runner treatment used in the gluing agent-coating step uponformation of the second coloring adhesion layer, kinds and amounts oforganic pigments adhered in organic pigment-adhering step upon formationof the second coloring adhesion layer, and linear load and treating timefor edge runner treatment used in the organic pigment-adhering step uponformation of the second coloring adhesion layer, were changed variously,thereby obtaining color agents for road marking material.

Meanwhile, in the intermediate particles 7, mixed particles containing50.0 parts by weight of the core particles and 50.0 parts by weight ofthe core particles 4 were used as the core particles.

The essential production conditions are shown in Tables 7 and 8, andvarious properties of the obtained color agents for road markingmaterial in the form of composite particles are shown in Table 9.

Example 25

2 kg of the color agent for a road marking material obtained in Example5 was mixed with 100 g of 2-ethyl hexanoic acid. The resultant mixturewas heated up to 120° C. for 30 minutes while stirring using a Henschelmixer, and then allowed to stand at 120° C. for 30 minutes. Thereafter,the mixture was cooled to room temperature for 30 minutes, therebyobtaining a surface-coated color agent for a road marking material.

The essential production conditions are shown in Table 10, and variousproperties of the obtained surface-coated color agents for road markingmaterial are shown in Table 11.

Examples 26 to 31

The same procedure as defined in Example 25 was conducted except thatkinds of color agents for road marking material, kinds and amounts ofcoating materials composed of a fatty acid, a fatty acid metal salt or acoupling agent, and kneading temperature and kneading time used incoating step using the Henschel mixer, were changed variously, therebyobtaining color agents for road marking material whose surface wascoated with the coating material.

The essential production conditions are shown in Table 10, and variousproperties of the obtained surface-coated color agents for road markingmaterial are shown in Table 11.

Examples 32 to 62 and Comparative Examples 5 to 10

<Road Marking Paint (First Class)>

The same procedure as defined in Example 1 was conducted except thatkinds of color agents for road marking material were changed variously,thereby obtaining road marking paints (first class).

The essential production conditions are shown in Tables 12 and 13, andvarious properties of the obtained road marking paints (first class) areshown in Tables 14 and 15.

Examples 63 to 93 and Comparative Examples 11 to 16

<Road Marking Paint (Second Class)>

The same procedure as defined in Example 1 was conducted except thatkinds of color agents for road marking material were changed variously,thereby obtaining road marking paints (second class).

The essential production conditions are shown in Tables 16 and 17, andvarious properties of the obtained road marking paints (second class)are shown in Tables 18 and 19.

Examples 94 to 124 and Comparative Examples 17 to 22

<Road Marking Paint (Third Class)>

The same procedure as defined in Example 1 was conducted except thatkinds of color agents for road marking material were changed variously,thereby obtaining road marking paints (third class).

The essential production conditions are shown in Tables 20 and 21, andvarious properties of the obtained road marking paints (third class) areshown in Tables 22 and 23.

TABLE 1 Properties of inorganic particles BET specific Average surfaceLight Kind of particle area Hue Refractive resistance core diametervalue a* value b* value C* value Hiding power index (ΔE* value)particles Kind Shape (μm) (m²/g) L* value (−) (−) (−) (−) (cm²/g) (−)(−) Core Titanium Granular 0.253 10.3 96.26 −0.64 −0.81 1.03 1,560 2.716.13 particles 1 oxide Core Titanium Granular 0.053 61.2 95.02 0.11 0.070.13 524 2.71 10.15 particles 2 oxide Core Zinc oxide Granular 0.18318.3 90.18 −2.22 3.76 4.37 730 2.03 5.84 particles 3 Core CalciumGranular 0.140 18.6 93.48 −0.07 0.94 0.94 46 1.52 6.99 particles 4carbonate Core Precipitated Granular 0.501 7.4 91.88 −0.46 3.25 3.29 631.62 6.17 particles 5 barium sulfate Core Silica Spherical 0.603 3.892.97 0.06 0.52 0.52 122 1.40 5.36 particles 6 Core Goethite Spindle-0.402 19.8 60.35 14.57 53.28 55.24 1,880 2.08 6.80 particles 7 shaped

TABLE 2 Surface-treating step Kind of Additives Coating material Corecore Calculated Amount Calculated Amount particles particles Kind as(wt. %) Kind as (wt. %) Core Core Sodium Al 1.0 A Al 0.98 particles 8particles 1 aluminate Core Core Sodium Al 1.5 A Al 1.48 particles 9particles 2 aluminate Water SiO₂ 1.0 S SiO₂ 0.99 glass #3 Core CoreWater SiO₂ 1.0 S SiO₂ 0.98 particles 10 particles 3 glass #3 Core CoreSodium Al 2.0 A Al 1.96 Particles 11 particles 4 aluminate Core CoreSodium Al 2.0 A Al 1.93 particles 12 particles 5 aluminate Water SiO₂0.5 S SiO₂ 0.47 glass #3 Core Core Aluminum Al 2.0 A Al 1.96 particles13 particles 6 sulfate Core Core Aluminum Al 1.0 A Al 0.97 particles 14particles 7 sulfate

TABLE 3 Properties of surface-treated white inorganic particlesProperties of surface-treated inorganic particles Light Average particleBET specific surface Hue Refractive resistance Kind of core diameterarea value a* b* value C* value Hiding power index (ΔE* value) particles(μm) (m²/g) L* value (−) value (−) (−) (−) (cm²/g) (−) (−) Core 0.25412.1 96.21 −0.52 −0.70 0.87 1,480 2.71 5.83 particles 8 Core 0.054 60.895.02 0.10 0.15 0.18 519 2.71 8.32 particles 9 Core 0.184 18.0 89.33−2.01 5.03 5.42 721 2.00 5.12 particles 10 Core 0.140 17.3 93.06 0.070.88 0.88 48 1.53 6.97 particles 11 Core 0.502 8.1 91.76 −0.44 3.21 3.2460 1.62 5.81 particles 12 Core 0.610 4.6 92.99 0.05 0.82 0.82 120 1.415.06 particles 13 Core 0.402 19.5 60.37 14.83 55.04 57.00 1,237 2.086.74 particles 14

TABLE 4 Properties of organic pigments Average BET specific Hue Lightparticle surface area a* resistance Organic Particle diameter value L*value value b* value (ΔE* value) pigments Kind shape (μm) (m²/g) (−) (−)(−) (−) Organic Pigment yellow Granular 0.15 41.7 69.51 38.31 76.9618.25 pigments Y-1 (disazo-based pigments) Organic Pigment yellowGranular 0.06 63.0 66.90 35.11 71.94 15.70 pigments Y-2 (condensedpolycyclic-type pigments) Organic Pigment red Granular 0.10 89.8 37.8144.03 24.09 15.47 pigments R-1 (condensed polycyclic-type pigments)Organic Pigment red Granular 0.20 43.3 42.64 42.36 30.96 17.92 pigmentsR-2 (azo rake-based pigments) Organic Pigment blue Granular 0.06 71.618.02 9.65 −23.57 10.83 pigments B-1 (phthalocyanine-based pigments)

TABLE 5 Production of color agent for road making material Coating stepwith gluing agent Coating Examples and Additives Edge runner treatmentamount Comparative Amount added Linear load Time Calculated as CExamples Kind of core particles Kind (wt. part) (N/cm) (Kg/cm) (min.)(wt. %) Example 2 Core particles 1 Methyltriethoxysilane 2.0 588 60 300.13 Example 3 Core particles 2 Isopropyltriisostearoyl 1.0 588 60 200.75 titanate Example 4 Core particles 3 Phenyltriethoxysilane 1.0 44145 30 0.36 Example 5 Core particles 4 Methylhydrogenpolysiloxane 2.0 58860 30 0.53 Example 6 Core particles 5 γ-aminopropyltriethoxysilane 1.5392 40 30 0.24 Example 7 Core particles 6 Methyltrimethoxysilane 2.0 44145 30 0.17 Example 8 Core particles 7 Phenyltriethoxysilane 2.0 392 4020 0.70 Example 9 Core particles 8 Methylhydrogenpolysiloxane 1.0 735 7520 0.27 Example 10 Core particles 9 Dimethyldimethoxysilane 1.5 588 6030 0.30 Example 11 Core particles 10 Polyvinyl alcohol 5.0 294 30 302.60 Example 12 Core particles 11 Methyltriethoxysilane 1.5 441 45 200.10 Example 13 Core particles 12 Methyltrimethoxysilane 3.0 441 45 200.26 Example 14 Core particles 13 γ-aminopropyltriethoxysilane 5.0 58860 30 0.77 Example 15 Core particles 14 Phenyltriethoxysilane 2.0 588 6030 0.71 Example 16 Core particles 1, 4 and 5 Methyltriethoxysilane 2.0588 60 30 0.13 Example 17 Core particles 5 and 8 Methyltriethoxysilane2.0 588 60 30 0.13 Comparative Core particles 1 — — — — — — Example 1Comparative Core particles 1 Methyltriethoxysilane 2 .0 588 60 30 0.13Example 2 Production of color agent for road making material Adhesionstep with organic pigments Organic pigments Amount adhered Examples andAmount Amount Edge runner treatment (calculated as Comparative adheredadhered Linear load Time C) Examples Kind (wt. part) Kind (wt. part)(N/cm) (Kg/cm) (min.) (wt. %) Example 2 Y-1 60.0 R-2 1.0 588 60 60 21.37Example 3 Y-1 40.0 R-1 1.0 588 60 60 16.43 Example 4 Y-2 20.0 R-1 0.6588 60 60 9.15 Example 5 Y-1 150.0 — — 735 75 60 34.04 Example 6 Y-130.0 R-2 1.0 588 60 60 19.22 Example 7 R-1 100.0 — — 735 75 30 30.16Example 8 B-1 20.0 — — 294 30 30 11.08 Example 9 Y-1 30.0 R-1 2.0 735 7520 13.75 Example 10 Y-1 60.0 R-2 1.5 735 75 60 21.52 Example 11 Y-2 30.0R-1 0.5 588 60 60 12.29 Example 12 Y-2 40.0 R-1 1.5 588 60 90 15.66Example 13 R-2 80.0 — — 441 45 20 22.34 Example 14 Y-2 60.0 R-2 1.0 58860 60 20.11 Example 15 Y-1 20.0 R-1 1.0 441 45 30 9.92 Example 16 Y-272.6 R-1 2.7 588 60 60 22.34 Example 17 Y-2 30.0 R-1 0.5 588 60 60 12.03Comparative Y-1 60.0 R-2 1.0 588 60 60 21.31 Example 1 Comparative Y-1750.0 — — 588 60 60 50.15 Example 2

TABLE 6 Properties of color agent for road making material DesorptionAverage BET specific Light percentage Examples and particle surface areaLightness Tinting Surface Heat resistance of organic Comparativediameter value (L* value) strength Hiding power activity resistance (ΔE*value) pigments Examples (μm) (m²/g) (−) (%) (cm²/g) (%) (° C.) (−) (%)Example 2 0.256 17.2 66.40 138 1,420 1.13 232 2.65 8.6 Example 3 0.05558.3 70.25 126 622 1.26 241 2.43 7.3 Example 4 0.184 19.6 71.38 121 8141.45 253 2.17 6.8 Example 5 0.146 24.8 68.04 144 443 1.04 228 2.85 9.2Example 6 0.502 13.9 65.78 133 425 1.09 229 2.59 7.4 Example 7 0.60711.9 40.33 130 682 1.09 230 2.69 9.0 Example 8 0.405 22.5 28.62 1261,820 1.49 266 2.80 8.6 Example 9 0.255 17.6 66.23 130 1,440 0.91 2522.11 4.1 Example 10 0.057 61.3 68.29 153 644 0.83 248 2.24 4.6 Example11 0.186 21.6 69.55 133 831 0.90 257 2.01 3.2 Example 12 0.142 19.765.32 142 414 0.88 246 1.95 4.5 Example 13 0.505 16.4 41.11 131 472 0.85253 2.13 4.4 Example 14 0.613 8.1 67.47 155 649 0.84 250 2.00 4.5Example 15 0.404 20.4 57.76 136 1,780 1.03 269 2.48 4.6 Example 16 0.29619.3 63.27 131 688 1.10 234 2.72 8.9 Example 17 0.379 15.1 68.33 142 6580.97 251 2.26 4.9 Comparative 0.253 20.9 62.13 100 1,304 2.46 183 6.9563.8 Example 1 Comparative 0.268 26.4 67.98 195 1,211 2.32 180 6.74 36.5Example 2 Comparative 0.259 18.9 69.64 98 1,290 2.06 188 5.66 34.2Example 3 Comparative 0.295 24.2 61.50 108 569 2.04 207 5.15 26.5Example 4

TABLE 7 Production of intermediate particles Coating step with gluingagent Additives Amount Edge runner treatment Coating amount IntermediateKind of core added Linear load Time Calculated as C particles particlesKind (wt. part) (N/cm) (Kg/cm) (min.) (wt. %) Intermediate CoreMethylhydrogen-polysiloxane 2.0 588 60 20 0.53 particles 1 particles 1Intermediate Core Methyl-triethoxysilane 1.0 294 30 30 0.07 particles 2particles 3 Intermediate Core Polyvinyl alcohol 2.0 441 45 30 1.06particles 3 particles 5 Intermediate Core γ-aminopropyl-triethoxysilane2.0 392 40 20 0.32 particles 4 particles 6 Intermediate CoreIsopropyltriiso-stearoyl 3.0 588 60 30 2.19 particles 5 particles 11titanate Intermediate Core Phenyl-triethoxysilane 1.5 441 45 20 0.54particles 6 particles 14 Intermediate Core Methylhydrogen-polysiloxane1.5 588 60 30 0.40 particles 7 particles 1 and 5 Production ofintermediate particles Adhesion step with organic pigments Amountadhered Organic pigments Edge runner treatment (calculated asIntermediate Amount adhered Linear load Time C) particles Kind (wt.part) (N/cm) (Kg/cm) (min.) (wt. %) Intermediate Y-1 80.0 588 60 3023.59 particles 1 Intermediate R-2 50.0 588 60 30 16.77 particles 2Intermediate Y-2 75.0 588 60 20 22.45 particles 3 Intermediate Y-2 45.0588 60 20 16.46 particles 4 Intermediate B-1 100.0 735 75 60 33.25particles 5 Intermediate Y-1 20.0 294 30 20 9.43 particles 6Intermediate Y-2 30.0 294 30 30 11.95 particles 7

TABLE 8 Production of color agent for road marking material Coating stepwith gluing agent Additives Coating Kind of Amount Edge runner treatmentamount intermediate added Linear load Time Calculated Examples particlesKind (wt. part) (N/cm) (Kg/cm) (min.) as C (wt. %) Example 18Intermediate Dimethyl- 3.0 588 60 30 0.95 particles 1 polysiloxaneExample 19 Intermediate Methylhydrogen- 2.0 441 45 20 0.53 particles 2polysiloxane Example 20 Intermediate Methyl- 2.0 294 30 20 0.13particles 3 triethoxysilane Example 21 Intermediate γ-aminopropyl- 1.5294 30 20 0.24 particles 4 triethoxysilane Example 22 IntermediateDimethyl- 1.0 294 30 20 0.32 particles 5 polysiloxane Example 23Intermediate Methyl- 2.0 588 60 30 0.13 particles 6 triethoxysilaneExample 24 Intermediate Dimethyl- 1.5 588 60 30 0.48 particles 7polysiloxane Production of color agent for road marking materialAdhesion step with organic pigments Organic pigments Edge runnertreatment Amount adhered Amount adhered Linear load Time (calculated asC) Examples Kind (wt. part) (N/cm) (Kg/cm) (min.) (wt. %) Example 18 R-11.5 294 30 20 0.86 Example 19 R-1 50.0 588 60 60 20.04 Example 20 Y-275.0 588 60 20 22.39 Example 21 R-2 1.0 294 30 20 0.48 Example 22 B-150.0 588 60 30 22.17 Example 23 B-1 10.0 441 45 30 6.10 Example 24 R-10.5 294 30 20 0.28

TABLE 9 Properties of color agent for road making material Average BETspecific Light Desorption particle surface area Lightness TintingSurface Heat resistance percentage diameter value (L* value) strengthHiding power activity resistance (ΔE* value) of organic Examples (μm)(m²/g) (−) (%) (cm²/g) (%) (° C.) (−) pigments (%) Example 18 0.256 16.868.55 132 1,460 1.12 233 2.66 7.1 Example 19 0.187 25.8 46.58 140 8141.03 228 2.71 8.1 Example 20 0.507 21.4 64.37 142 515 1.03 231 2.48 8.3Example 21 0.605 6.9 67.29 130 631 1.10 230 2.40 6.4 Example 22 0.14624.1 20.54 146 433 0.74 259 1.87 8.4 Example 23 0.403 23.5 38.90 1291,760 1.05 270 2.75 7.5 Example 24 0.379 15.3 68.05 140 651 1.13 2442.64 6.9

TABLE 10 Production of surface-coated road marking material Coating stepwith fatty acid, fatty acid metal salt or coupling agent Coating amountKind of Additives Kneading (calculated composite Amount addedtemperature Kneading time as C) Examples particles Kind (wt. part) (°C.) (min.) (wt. %) Example 25 Example 5 2-ethyl hexanoic 5.0 120 30 3.17acid Example 26 Example 6 Zinc stearate 1.5 120 30 1.00 Example 27Example 8 γ-aminopropyl- 1.0 120 30 0.16 triethoxysilane Example 28Example 11 Zinc stearate 1.0 80 30 0.67 Example 29 Example 14 Magnesium1.0 120 30 0.72 stearate Example 30 Example 17 γ-aminopropyl- 3.0 80 300.59 triethoxysilane Example 31 Example 18 Calcium stearate 1.5 60 301.05

TABLE 11 Properties of surface-coated color agent for road makingmaterial Average BET specific Light Desorption particle surface areaLightness Tinting Surface Heat resistance percentage diameter value (L*value) strength Hiding power activity resistance (ΔE* value) of organicExamples (μm) (m²/g) (−) (%) (cm²/g) (%) (° C.) (−) pigments (%) Example25 0.147 23.6 68.37 146 440 0.99 229 2.74 4.6 Example 26 0.503 13.565.92 134 419 1.04 231 2.49 3.4 Example 27 0.406 21.3 28.85 127 1,8101.36 267 2.73 4.1 Example 28 0.187 20.5 69.81 135 828 0.88 258 1.96 2.9Example 29 0.615 7.8 67.62 157 642 0.81 253 1.95 3.2 Example 30 0.38014.7 68.59 143 651 0.92 252 2.18 2.7 Example 31 0.257 16.0 68.70 1351,455 0.97 236 2.57 5.9

TABLE 12 Production of road marking paint (first class) Color agent forroad marking paint Amount Amount blended blended Examples Kind (wt.part) Kind (wt. part) Example 32 Example 2 15.0 — — Example 33 Example 315.0 — — Example 34 Example 4 15.0 — — Example 35 Example 5 15.0 — —Example 36 Example 6 15.0 — — Example 37 Example 7 15.0 — — Example 38Example 8 15.0 — — Example 39 Example 9 15.0 — — Example 40 Example 1015.0 — — Example 41 Example 11 15.0 — — Example 42 Example 12 15.0 — —Example 43 Example 13 15.0 — — Example 44 Example 14 15.0 — — Example 45Example 15 15.0 — — Example 46 Example 16 15.0 — — Example 47 Example 1715.0 — — Example 48 Example 18 15.0 — — Example 49 Example 19 15.0 — —Example 50 Example 20 15.0 — — Example 51 Example 21 15.0 — — Example 52Example 22 15.0 — — Example 53 Example 23 15.0 — — Example 54 Example 2415.0 — — Example 55 Example 25 15.0 — — Example 56 Example 26 15.0 — —Example 57 Example 27 15.0 — — Example 58 Example 28 15.0 — — Example 59Example 29 15.0 — — Example 60 Example 30 15.0 — — Example 61 Example 3115.0 — — Example 62 Example 2 7.5 Example 6 7.5

TABLE 13 Production of road marking paint (first class) Color agent forroad marking paint Amount Amount blended blended Comparative (wt. (wt.Examples Kind part) Kind part) Comparative Organic 14.5 Organic 0.5Example 5 pigments pigments Y-1 R-2 Comparative Organic 15.0 — — Example6 pigments R-2 Comparative Comparative 15.0 — — Example 7 Example 1Comparative Comparative 15.0 — — Example 8 Example 2 ComparativeComparative 15.0 — — Example 9 Example 3 Comparative Comparative 15.0 —— Example 10 Example 4

TABLE 14 Properties of road marking paint (first class) Light AgingRetro- Contrast Alkali Abrasion resistance resistance reflective ratioresistance resistance (ΔE* value) (ΔE* value) property Examples (−) (−)(mg) (−) (−) (−) Example 32 0.96 4 313 3.41 1.92 4 Example 33 0.86 5 3343.20 1.95 3 Example 34 0.91 5 308 2.95 1.91 4 Example 35 0.83 5 322 3.621.88 3 Example 36 0.84 5 325 3.48 1.90 3 Example 37 0.85 5 328 3.43 1.85— Example 38 0.96 5 340 3.51 2.17 — Example 39 0.97 5 271 2.88 1.56 4Example 40 0.87 4 287 2.98 1.59 3 Example 41 0.91 5 279 2.76 1.50 4Example 42 0.82 5 262 2.69 1.41 3 Example 43 0.85 5 277 2.92 1.44 —Example 44 0.84 4 298 2.75 1.38 3 Example 45 0.97 5 295 3.22 1.77 3Example 46 0.90 4 320 3.44 1.91 3 Example 47 0.92 5 298 3.13 1.63 4Example 48 0.97 5 315 3.39 1.90 4 Example 49 0.92 4 324 3.40 1.89 —Example 50 0.84 5 318 3.42 1.88 3 Example 51 0.83 4 309 3.18 1.71 3Example 52 0.82 5 263 2.65 1.33 — Example 53 0.96 5 277 3.27 1.94 —Example 54 0.92 5 320 3.31 1.62 4 Example 55 0.84 5 248 3.49 1.85 3Example 56 0.85 5 242 3.41 1.87 3 Example 57 0.96 5 239 3.47 2.14 —Example 58 0.92 5 229 2.68 1.44 4 Example 59 0.87 4 210 2.65 1.40 3Example 60 0.92 5 243 3.39 1.60 4 Example 61 0.97 5 199 3.26 1.79 4Example 62 0.91 4 330 3.50 1.93 4

TABLE 15 Properties of road marking paint (first class) Light AgingRetro- Contrast Alkali Abrasion resistance resistance reflectiveComparative ratio resistance resistance (ΔE* value) (ΔE* value) propertyExamples (−) (−) (mg) (−) (−) (−) Comparative 0.76 2 511 18.26 3.58 1Example 5 Comparative 0.69 1 484 18.84 3.46 — Example 6 Comparative 0.742 572 7.81 4.77 2 Example 7 Comparative 0.77 3 549 7.65 4.60 1 Example 8Comparative 0.73 3 533 6.52 3.92 2 Example 9 Comparative 0.82 2 438 5.072.71 2 Example 10

TABLE 16 Production of road marking paint (second class) Color agent forroad marking paint Amount Amount blended blended Examples Kind (wt.part) Kind (wt. part) Example 63 Example 2 15.0 — — Example 64 Example 315.0 — — Example 65 Example 4 15.0 — — Example 66 Example 5 15.0 — —Example 67 Example 6 15.0 — — Example 68 Example 7 15.0 — — Example 69Example 8 15.0 — — Example 70 Example 9 15.0 — — Example 71 Example 1015.0 — — Example 72 Example 11 15.0 — — Example 73 Example 12 15.0 — —Example 74 Example 13 15.0 — — Example 75 Example 14 15.0 — — Example 76Example 15 15.0 — — Example 77 Example 16 15.0 — — Example 78 Example 1715.0 — — Example 79 Example 18 15.0 — — Example 80 Example 19 15.0 — —Example 81 Example 20 15.0 — — Example 82 Example 21 15.0 — — Example 83Example 22 15.0 — — Example 84 Example 23 15.0 — — Example 85 Example 2415.0 — — Example 86 Example 25 15.0 — — Example 87 Example 26 15.0 — —Example 88 Example 27 15.0 — — Example 89 Example 28 15.0 — — Example 90Example 29 15.0 — — Example 91 Example 30 15.0 — — Example 92 Example 3115.0 — — Example 93 Example 2 7.5 Example 6 7.5

TABLE 17 Production of road marking paint (second class) Color agent forroad marking paint Amount Amount blended blended Comparative (wt. (wt.Examples Kind part) Kind part) Comparative Organic 14.5 Organic 0.5Example 11 pigments pigments Y-1 R-1 Comparative Organic 15.0 — —Example 12 pigments B-1 Comparative Comparative 15.0 — — Example 13Example 1 Comparative Comparative 15.0 — — Example 14 Example 2Comparative Comparative 15.0 — — Example 15 Example 3 ComparativeComparative 15.0 — — Example 16 Example 4

TABLE 18 Properties of road marking paint (second class) Contrast AlkaliAbrasion ratio resistance resistance Examples (−) (−) (mg) Example 630.97 4 275 Example 64 0.86 5 297 Example 65 0.92 5 268 Example 66 0.84 5281 Example 67 0.85 5 284 Example 68 0.85 5 288 Example 69 0.97 5 294Example 70 0.98 5 233 Example 71 0.88 4 238 Example 72 0.91 5 237Example 73 0.83 5 228 Example 74 0.85 5 236 Example 75 0.85 4 247Example 76 0.98 5 240 Example 77 0.91 4 280 Example 78 0.93 5 261Example 79 0.98 5 280 Example 80 0.92 4 295 Example 81 0.85 5 287Example 82 0.83 4 298 Example 83 0.83 5 233 Example 84 0.97 5 241Example 85 0.92 5 294 Example 86 0.84 5 197 Example 87 0.86 5 197Example 88 0.97 5 195 Example 89 0.92 5 190 Example 90 0.88 4 188Example 91 0.93 5 210 Example 92 0.98 5 172 Example 93 0.92 4 316Properties of road marking paint (second class) Light Aging Retro-resistance resistance reflective (ΔE* value) (ΔE* value) propertyExamples (−) (−) (−) Example 63 3.36   1.90  4 Example 64 3.15   1.94  4Example 65 2.91   1.89  4 Example 66 3.58   1.85  3 Example 67 3.44  1.89  3 Example 68 3.40   1.82 — Example 69 3.47   2.14 — Example 702.83   1.54  4 Example 71 2.96   1.56  4 Example 72 2.75   1.47  4Example 73 2.65   1.38  4 Example 74 2.88   1.41 — Example 75 2.72  1.35  3 Example 76 3.20   1.75  3 Example 77 3.41   1.88  3 Example 783.09   1.60  4 Example 79 3.34   1.88  4 Example 80 3.36   1.86 —Example 81 3.37   1.85  3 Example 82 3.15   1.69  4 Example 83 3.60  1.30 — Example 84 3.41   1.91 — Example 85 3.27   1.60  4 Example 863.45   1.84  4 Example 87 3.38   1.86  3 Example 88 3.42   2.13 —Example 89 2.62   1.41  4 Example 90 2.60   1.39  4 Example 91 3.35  1.59  4 Example 92 3.20   1.77  4 Example 93 3.45   1.92  4

TABLE 19 Properties of road marking paint (second class) Contrast AlkaliAbrasion Comparative ratio resistance resistance Examples (−) (−) (mg)Comparative 0.76 2 492 Example 11 Comparative 0.70 1 455 Example 12Comparative 0.75 2 520 Example 13 Comparative 0.74 3 503 Example 14Comparative 0.73 3 501 Example 15 Comparative 0.83 2 416 Example 16Properties of road marking paint (second class) Light Aging Retro-resistance resistance reflective Comparative (ΔE* value) (ΔE* value)property Examples (−) (−) (−) Comparative 18.22 3.55  1 Example 11Comparative 18.69 3.44 — Example 12 Comparative 7.79 4.74  2 Example 13Comparative 7.61 4.58  1 Example 14 Comparative 6.48 3.90  2 Example 15Comparative 5.04 2.68  2 Example 16

TABLE 20 Production of road marking paint (third class) Color agent forroad marking paint Amount Amount blended blended Examples Kind (wt.part) Kind (wt. part) Example 94 Example 2 5.0 — — Example 95 Example 35.0 — — Example 96 Example 4 5.0 — — Example 97 Example 5 5.0 — —Example 98 Example 6 5.0 — — Example 99 Example 7 5.0 — — Example 100Example 8 5.0 — — Example 101 Example 9 5.0 — — Example 102 Example 105.0 — — Example 103 Example 11 5.0 — — Example 104 Example 12 5.0 — —Example 105 Example 13 5.0 — — Example 106 Example 14 5.0 — — Example107 Example 15 5.0 — — Example 108 Example 16 5.0 — — Example 109Example 17 5.0 — — Example 110 Example 18 5.0 — — Example 111 Example 195.0 — — Example 112 Example 20 5.0 — — Example 113 Example 21 5.0 — —Example 114 Example 22 5.0 — — Example 115 Example 23 5.0 — — Example116 Example 24 5.0 — — Example 117 Example 25 5.0 — — Example 118Example 26 5.0 — — Example 119 Example 27 5.0 — — Example 120 Example 285.0 — — Example 121 Example 29 5.0 — — Example 122 Example 30 5.0 — —Example 123 Example 31 5.0 — — Example 124 Example 2 2.5 Example 6 2.5

TABLE 21 Production of road marking paint (third class) Color agent forroad marking paint Amount Amount Comparative blended blended ExamplesKind (wt. part) Kind (wt. part) Comparative Organic 4.9 Organic 0.1Example 17 pigments pigments Y-1 R-1 Comparative Organic 5.0 — — Example18 pigments B-1 Comparative Comparative 5.0 — — Example 19 Example 1Comparative Comparative 5.0 — — Example 20 Example 2 ComparativeComparative 5.0 — — Example 21 Example 3 Comparative Comparative 5.0 — —Example 22 Example 4

TABLE 22 Properties of road marking paint (third class) Alkaliresistance Abrasion resistance Examples (−) (mg) Example 94 4 147Example 95 5 165 Example 96 5 143 Example 97 5 150 Example 98 5 156Example 99 5 154 Example 100 5 161 Example 101 5 105 Example 102 4 118Example 103 5 113 Example 104 5  99 Example 105 5 110 Example 106 4 128Example 107 5 114 Example 108 4 156 Example 109 5 143 Example 110 5 139Example 111 4 144 Example 112 5 141 Example 113 4 150 Example 114 5 106Example 115 5 114 Example 116 5 148 Example 117 5  88 Example 118 5  92Example 119 5  85 Example 120 5  85 Example 121 4  79 Example 122 5  96Example 123 5  72 Example 124 4 189 Properties of road marking paint(third class) Light Aging Retro- resistance resistance reflective (ΔE*value) (ΔE* value) property Examples (−) (−) (−) Example 94 3.21 1.89 4Example 95 3.02 1.91 4 Example 96 2.78 1.84 4 Example 97 3.45 1.83 4Example 98 3.29 1.86 3 Example 99 3.26 1.80 — Example 100 3.34 2.10 —Example 101 2.68 1.51 4 Example 102 2.79 1.55 4 Example 103 2.61 1.45 4Example 104 2.50 1.34 4 Example 105 2.72 1.39 — Example 106 2.58 1.33 4Example 107 3.07 1.71 3 Example 108 3.26 1.86 3 Example 109 2.95 1.57 4Example 110 3.21 1.85 4 Example 111 3.22 1.81 — Example 112 3.14 1.82 3Example 113 2.99 1.66 4 Example 114 2.48 1.27 — Example 115 3.29 1.92 —Example 116 3.11 1.55 4 Example 117 3.26 1.82 4 Example 118 3.22 1.84 3Example 119 3.37 2.10 — Example 120 2.50 1.37 4 Example 121 2.43 1.35 4Example 122 3.20 1.55 4 Example 123 3.17 1.74 4 Example 124 3.33 1.90 4

TABLE 23 Properties of road marking paint (third class) ComparativeAlkali resistance Abrasion resistance Examples (−) (mg) Comparative 2221 Example 17 Comparative 1 214 Example 18 Comparative 2 245 Example 19Comparative 3 234 Example 20 Comparative 3 226 Example 21 Comparative 2196 Example 22 Properties of road marking paint (third class) LightAging Retro- resistance resistance reflective Comparative (ΔE* value)(ΔE* value) property Examples (−) (−) (−) Comparative 18.06  3.52 1Example 17 Comparative 18.65  3.41 — Example 18 Comparative 7.64 4.71 2Example 19 Comparative 7.87 4.55 1 Example 20 Comparative 6.36 3.92 2Example 21 Comparative 5.02 2.66 2 Example 22

1. A color agent for a road marking material comprising compositeparticles having an average particle diameter of 0.01 to 10.0 μm, saidcomposite particles comprising: inorganic particles; a gluing agentcoating layer formed on surface of said inorganic particle; an organicpigment coat formed onto said gluing agent coating layer in an amount offrom 1 to 500 parts by weight based on 100 parts by weight of saidinorganic particles; and a surface coating layer composed of at leastone material selected from the group consisting of a fatty acid, a fattyacid metal salt and a coupling agent, which is formed on said organicpigment coat in an amount of 0.1 to 10.0% by weight based on the totalweight of the composite particles including the surface coating layer.2. A color agent according to claim 1, wherein said gluing agent is anorganosilicon compound, a coupling agent, an oligomer compound or apolymer compound.
 3. A color agent according to claim 1, wherein saidinorganic particles are white pigments having a refractive index of notless than 2.0, extender pigments having a refractive index of less than2.0 or the mixture thereof.
 4. A color agent according to claim 1,wherein said inorganic particles are particles each having on at least apart of the surface thereof, a coating layer comprising at least onecompound selected from the group consisting of hydroxides of aluminum,oxides of aluminum, hydroxides of silicon and oxides of silicon.
 5. Acolor agent according to claim 1, wherein said fatty acid is a saturatedor unsaturated fatty acid having 12 to 22 carbon atoms.
 6. A color agentaccording to claim 1, wherein said fatty acid metal salt is a salt of asaturated or unsaturated fatty acid having 12 to 22 carbon atoms, and analkali earth metal selected from magnesium, calcium, strontium andbarium, an alkali metal selected from lithium, sodium and potassium, ora metal selected from zinc, aluminum, copper, iron, lead and tin.
 7. Acolor agent according to claim 1, wherein said coupling agent is asilane-based coupling agent selected from the group consisting ofγ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane,vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane,γ-chloropropyltrimethoxysilane, γ-chloropropylmethyldichlorosilane,γ-chloropropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane,γ-glycidoxypropyltrimethoxysilane,γ-glycidoxypropylmethyldiethoxysilane,γ-methacryloxypropyltrimethoxysilane,γ-methacryloxypropylmethyldimethoxysilane,N-β-(aminoethyl)-β-aminopropyltrimethoxysilane,N-β(aminoethyl)-β-aminopropylmethyldimethoxysilane,vinyltris(β-methoxyethoxy)silane,β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane andN-phenyl-γ-aminopropyltrimethoxysilane.
 8. A color agent according toclaim 1, wherein the amount of said fatty acid, said fatty acid metalsalt or said coupling agent is 0.1 to 10.0% by weight, calculated as C,based on the weight of the color agent including the surface coatinglayer made of the fatty acid, the fatty acid metal salt or the couplingagent.
 9. A color agent according to claim 1, wherein said color agenthas a BET specific surface area value of 0.5 to 500 m²/g, a tintingstrength of not less than 110%, a hiding power of not less than 200cm²/g, a heat resistance of not less than 180° C., a light resistance(ΔE* value) of not more than 5.0 and a surface activity of not more than1.5%.
 10. A color agent according to claim 1, wherein said surfacecoating layer is present in an amount of 0.2 to 7.5% by weight based onthe total weight of the composite particles including the surfacecoating layer.
 11. A color agent according to claim 1, wherein saidsurface coating layer is present in an amount of 0.3 to 5.0% by weightbased on the total weight of the composite particles including thesurface coating layer.
 12. A color agent for a road marking materialcomprising composite particles having an average particle diameter of0.01 to 10.0 μm, said composite particles comprising: inorganicparticles; a gluing agent coating layer formed on surface of saidinorganic particle; an organic pigment coat formed onto said gluingagent coating layer in an amount of from 1 to 500 parts by weight basedon 100 parts by weight of said inorganic particles; and a surfacecoating layer composed of at least one material selected from the groupconsisting of a fatty acid, a fatty acid metal salt and a couplingagent, which is formed on said organic pigment coat in an amount of 0.1to 10.0% by weight based on the total weight of the composite particlesincluding the surface coating layer wherein the road marking materialhas an abrasion resistance of not more than 400 mg measured according toJIS K
 5665. 13. A color agent according to claim 12, wherein saidabrasion resistance is not more than 350 mg.
 14. A color agent accordingto claim 12, wherein said gluing agent is an organosilicon compound, acoupling agent, an oligomer compound or a polymer compound.
 15. A coloragent according to claim 12, wherein said inorganic particles are whitepigments having a refractive index of not less than 2.0, extenderpigments having a refractive index of less than 2.0 or the mixturethereof.
 16. A color agent according to claim 12, wherein said inorganicparticles are particles each having on at least a part of the surfacethereof, a coating layer comprising at least one compound selected fromthe group consisting of hydroxides of aluminum, oxides of aluminum,hydroxides of silicon and oxides of silicon.
 17. A color agent accordingto claim 12, wherein said fatty acid is a saturated or unsaturated fattyacid having 12 to 22 carbon atoms.
 18. A color agent according to claim12, wherein said fatty acid metal salt is a salt of a saturated orunsaturated fatty acid having 12 to 22 carbon atoms, and an alkali earthmetal selected from magnesium, calcium, strontium and barium, an alkalimetal selected from lithium, sodium and potassium, or a metal selectedfrom zinc, aluminum, copper, iron, lead and tin.
 19. A color agentaccording to claim 12, wherein said coupling agent is a silane-basedcoupling agent selected from the group consisting ofγ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane,vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane,γ-chloropropyltrimethoxysilane, γ-chloropropylmethyldichlorosilane,γ-chloropropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane,γ-glycidoxypropyltrimethoxysilane,γ-glycidoxypropylmethyldiethoxysilane,γ-methacryloxypropyltrimethoxysilane,γ-methacryloxypropylmethyldimethoxysilane,N-β(aminoethyl)-β-aminopropyltrimethoxysilane,N-β(aminoethyl)-β-aminopropylmethyldimethoxysilane,vinyltris(β-methoxyethoxy)silane,β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane andN-phenyl-γ-aminopropyltrimethoxysilane.
 20. A color agent according toclaim 12, wherein the amount of said fatty acid, said fatty acid metalsalt or said coupling agent is 0.1 to 10.0% by weight, calculated as C,based on the weight of the color agent including the surface coatinglayer made of the fatty acid, the fatty acid metal salt or the couplingagent.
 21. A color agent according to claim 12, wherein said color agenthas a BET specific surface area value of 0.5 to 500 m²/g, a tintingstrength of not less than 110%, a hiding power of not less than 200cm²/g, a heat resistance of not less than 180° C., a light resistance(ΔE* value) of not more than 5.0 and a surface activity of not more than1.5%.